Phonological constraints on children's production of English third person singular -s

Asynchronization at the phonology-morphology interface: A case study of an atypically developing Hebrew-acquiring boy

In this paper, we present a case study of an atypically developing Hebrew-acquiring boy (YV), in comparison with three typically developing boys. Drawing on data from longitudinal studies, we examined the development of two verbal suffixes, -im 'ms.pl.pres' and -ti '1.sg.past', with reference to two prosodic structures that these suffixes assume - word final codas for -im and trisyllabic words for -ti (e.g. bon-ím 'they build', kará-ti 'I read'). We found that YV's developmental trajectory was similar to that of the three boys in both phonology and morphology, each module independently; the deviant phenomena were found at the interface between phonology and morphology. The typically developing boys produced the relevant phonological structures in bare stems before they produced them in suffixed forms. YV, however, proceeded in the opposite order; he produced the final m in -im verbs before mastering word final codas in bare stems; similarly, he produced trisyllabic forms in -ti verbs before mastering them in bare stems. We attribute this deviance to asynchronization between phonological (prosodic) and morphological development. That is, YV's phonology lagged behind his morphology, but this lag did not block the morphological development as it would have in synchronized development.

Effect of Predicate Types on the Production of Copula "Is" in 2-Year-Old Children Who Speak General American English

PURPOSE

Prior work has shown that subject types affected the production of copula BE in young children who spoke General American English (GAE). However, the role of predicate types on the production of copula BE remains unclear. This study examined how predicate types affected the production of copula "is" in young GAE-speaking children.

METHOD

Seventeen 2-year-old children with typical language development who spoke GAE were included in this study. Children's production rate of copula "is" in sentences with nominal (e.g., The dog is a king ), permanent-adjectival (e.g., The dog is white ), temporary-adjectival (e.g., The dog is very hot ), or locative (e.g., The dog is outside ) predicates was examined using an elicited repetition task.

RESULTS

Two-year-old children who spoke GAE were more likely to repeat copula "is" correctly with nominal, permanent-adjectival, and temporary-adjectival predicates than with locative predicates after sentence length was controlled. There were no other significant differences between predicate types.

CONCLUSIONS

Overall, locative predicates are the least facilitative for the production of copula "is" as compared to other predicate types. Predicate types, especially locative predicates, should be considered when the clinician creates sentences to evaluate the production of copula BE and to provide intervention for GAE-speaking children.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22630726.

Input effects in the acquisition of verb inflection: Evidence from Emirati Arabic

This study investigates the acquisition of the Imperfective verb inflection paradigm in Emirati Arabic (EA), to determine whether the learning process is sensitive to the phonological and typological properties of the input. We collected data from 48 participants aged 2;7 to 5;9 years, using an elicited production paradigm. Input frequencies of inflectional contexts, verb types and tokens were obtained from corpora of child-directed and adult EA. Children's accuracy was inversely related to the input frequency of inflectional contexts, but not related to type and token frequency or phonological neighborhood density. Token frequency interacted with age, such that younger children performed considerably worse on low-frequency tokens, but older children performed equally well on high- and low-frequency tokens. We conclude that learning is input-driven, but that a sufficiently regular paradigm allows children to eventually generalise across all items earlier than in previously studied European languages.

A profile of expressive inflectional morphology in early school-age children with developmental language disorder

Previous research has established that children with developmental language disorder (DLD) have difficulties producing inflectional morphology, in particular, finiteness marking. However, other categories of inflectional morphology, such as possessive 's nominal inflection remain relatively unexplored. Analyses of the characteristics for marking inflection, such as allomorphic categories, may increase our understanding of patterns within disordered grammar to inform the design of interventions and target selection. Data from n = 30 early school-aged children (M = 75 months, SD = 3.38, range = 69-81 months) with DLD were analysed to develop a profile of inflectional morphology skills. Morphological categories included expressive regular past tense, third person singular, and possessive 's. Skills were profiled using an elicitation task. The relationships between expressive morphosyntax, and phonological short-term memory and working memory were also explored. Children demonstrated low accuracy in performance across all inflectional categories, including possessive 's. There were no significant differences between productions of different morphemes, but syllabic allomorphs ([əd]; [əz]) were produced with significantly lower accuracy than segmental allomorphs ([d], [t]; [z], [s]) across all morphological categories. All correlations between expressive morphosyntax and measures of memory were non-significant. Children with DLD show broad deficits in the ability to mark for inflection, including possessive 's; this has implications for theories explaining DLD. Findings may contribute to the design of urgently needed interventions for this clinical population.

Produced, but not 'productive': Mandarin-speaking pre-schoolers' challenges acquiring L2 English plural morphology

It is often assumed that pre-schoolers learn a second language (L2) with ease, even for structures that are absent in their L1, such as Mandarin-speaking pre-schoolers learning L2 English grammatical inflections (e.g., ducks, horses). However, while the results from Study 1 showed that such learners can imitate plural words (age = 3;5, N = 20), Studies 2 and 3 showed that they cannot yet generate or comprehend plural morphology (Study 2: age = 4;8, N = 20; Study 3: age = 4;1, N = 20), raising questions about when this is achieved. These findings have important implications for school readiness, as well as for identifying those at risk of developmental language disorders.

A Phonetic Account of Spanish-English Bilinguals’ Divergence with Agreement

Does bilingual language influence in the domain of phonetics impact the morphosyntactic domain? Spanish gender is encoded by word-final, unstressed vowels (/a e o/), which may diphthongize in word-boundary vowel sequences. English neutralizes unstressed final vowels and separates across-word vocalic sequences. The realization of gender vowels as schwa, due to cross-linguistic influence, may remain undetected if not directly analyzed. To explore the potential over-reporting of gender accuracy, we conducted parallel phonetic and morphosyntactic analyses of read and semi-spontaneous speech produced by 11 Monolingual speakers and 13 Early and 13 Late Spanish-English bilinguals. F1 and F2 values were extracted at five points for all word-final unstressed vowels and vowel sequences. All determiner phrases (DPs) from narratives were coded for morphological and contextual parameters. Early bilinguals exhibited clear patterns of vowel centralization and higher rates of hiatuses than the other groups. However, the morphological analysis yielded very few errors. A follow-up integrated analysis revealed that /a and o/ were realized as centralized vowels, particularly with [+Animate] nouns. We propose that bilinguals’ schwa-like realizations can be over-interpreted as target Spanish vowels. Such variable vowel realization may be a factor in the vulnerability to attrition in gender marking in Spanish as a heritage language.

Why jumped is so difficult: tense/aspect marking in Mandarin-English bilingual children

Learning to mark for tense in a second language is notoriously difficult for speakers of a tenseless language like Chinese. In this study we test two reasons for these difficulties in Chinese-English sequential bilingual children: (1) morphophonological transfer (i.e., avoidance of complex codas), and (2) interpretation of -ed as an aspect marker of completion, like the Mandarin -le. Mandarin-English bilingual children and age-matched monolinguals did a cartoon retell task. The verbs used in the stories were coded for accuracy in English, telicity, and suppliance of -ed or -le. The results were consistent with morphophonological transfer: the bilingual children were more accurate with irregular past forms in English than regular forms. The results were also consistent with the bilingual children's interpretation of -ed as an aspect marker: most of their production of -ed was on telic verbs. We discuss possible reasons for the children's interpretation of -ed as an aspect marker.

The Acquisition of Productive Plural Morphology by Children With Hearing Loss

Purpose Normal-hearing (NH) children acquire plural morphemes at different rates, with the segmental allomorphs /-s, -z/ (e.g., cat-s) being acquired before the syllabic allomorph /-əz/ (e.g., bus-es). Children with hearing loss (HL) have been reported to show delays in the production of plural morphology, raising the possibility that this might be due to challenges acquiring different types of lexical/morphological representations. This study therefore examined the comprehension of plural morphology by 3- to 7-year-olds with HL and compared this with performance by their NH peers. We also investigated comprehension as a function of wearing hearing aids (HAs) versus cochlear implants (CIs). Method Participants included 129 NH children aged 3-5 years and 25 children with HL aged 3-7 years (13 with HAs, 12 with CIs). All participated in a novel word two-alternative forced-choice task presented on an iPad. The task tested comprehension of the segmental (e.g., teps, mubz) and syllabic (e.g., kosses) plural, as well as their singular counterparts (e.g., tep, mub, koss). Results While the children with NH were above chance for all conditions, those with HL performed at chance. As a group, the performance of the children with HL did not improve with age. However, results suggest possible differences between children with HAs and those with CIs, where those with HAs appeared to be in the process of developing representations of consonant-vowel-consonant singulars. Conclusions Results suggest that preschoolers with HL do not yet have a robust representation of plural morphology for words they have not heard before. However, those with HAs are beginning to access the singular/plural system as they get older.

Acquiring diminutive allomorphs: taking item-specific characteristics into account

Phonological characteristics and frequencies of stems and allomorphs have been explored as possible factors causing differences in production accuracies between allomorphic forms. However, previous findings are not consistent and the relative contributions of these factors are unclear. This study investigated target and erroneous productions of the Dutch diminutive, which has five allomorphs with varying type frequencies and of which the selection depends on the phonological characteristics of the stems. Typically developing children (N = 115, 5;1-10;3) were tested on their production of real and nonce diminutives. Linear mixed effects modelling was used to analyse the data taking nonverbal IQ into account. Type frequencies of the allomorphs and differences in phonological characteristics of the stems were found to be related to differences in production accuracies between the allomorphs. However, phonological characteristics of the stems appeared to have a bigger impact, mainly due to the phonological complexity of these characteristics.

Five overarching factors central to grammatical learning and treatment in children with developmental language disorder

BACKGROUND

During grammatical treatment of children with developmental language disorder (DLD), it is natural for therapists to focus on the grammatical details of the target language that give the children special difficulty. However, along with the language-specific features of the target (e.g., for English, add -s to verbs in present tense, third-person singular contexts), there are overarching factors that operate to render the children's learning task more, or less, challenging, depending on the particular target.

AIMS

To identify five such factors that can play a role in the grammatical learning of children with DLD. We use English as our example language and provide supporting evidence from a variety of other languages.

MAIN CONTRIBUTION

We show that the relative degree of English-speaking children's difficulty with particular grammatical details can be affected by the extent to which these details involve: (1) bare stems; (2) opportunities for grammatical case confusion; (3) prosodic challenges; (4) grammatical and lexical aspect; and (5) deviations from canonical word order.

CONCLUSIONS

During treatment, therapists will want to consider not only the English-specific features of grammatical targets but also how these more general factors can be taken into account to increase the children's success.

Why do children pay more attention to grammatical morphemes at the ends of sentences?

Children pay more attention to the beginnings and ends of sentences rather than the middle. In natural speech, ends of sentences are prosodically and segmentally enhanced; they are also privileged by sensory and recall advantages. We contrasted whether acoustic enhancement or sensory and recall-related advantages are necessary and sufficient for the salience of grammatical morphemes at the ends of sentences. We measured 22-month-olds' listening times to grammatical and ungrammatical sentences with third person singular -s. Crucially, by cross-splicing the speech stimuli, acoustic enhancement and sensory and recall advantages were fully crossed. Only children presented with the verb in sentence-final position, a position with sensory and recall advantages, distinguished between the grammatical and ungrammatical sentences. Thus, sensory and recall advantages alone were necessary and sufficient to make grammatical morphemes at ends of sentences salient. These general processing constraints privilege ends of sentences over middles, regardless of the acoustic enhancement.

The effects of phonological skills and vocabulary on morphophonological processing

Morphophonological processing involves the phonological analysis of morphemes. Item-specific phonological characteristics have been shown to influence morphophonological skills in children. This study investigates the relative contributions of broad phonological skills and vocabulary to production and judgement accuracies of the Dutch past tense and diminutive, two morphophonological processes. Typically developing children (age 5;0-10;0, N = 114) were asked to produce and judge real and nonce diminutives and regular past tenses. Phonological processing skills were measured using a phonological awareness, digit span and nonword repetition task; vocabulary using the PPVT. Phonological skills and vocabulary contributed significantly to the production and judgement of the past tense and diminutive. The results underline the relation between phonological skills and the lexicon and the processing of morphophonology. These findings go further than showing the importance of the item-specific phonological context of the stem and suffix: they indicate that more general skills in the domain of phonology and vocabulary are involved.

Influences of Phonological Context on Tense Marking in Spanish-English Dual Language Learners

PURPOSE

The emergence of tense-morpheme marking during language acquisition is highly variable, which confounds the use of tense marking as a diagnostic indicator of language impairment in linguistically diverse populations. In this study, we seek to better understand tense-marking patterns in young bilingual children by comparing phonological influences on marking of 2 word-final tense morphemes.

METHOD

In spontaneous connected speech samples from 10 Spanish-English dual language learners aged 56-66 months (M = 61.7, SD = 3.4), we examined marking rates of past tense -ed and third person singular -s morphemes in different environments, using multiple measures of phonological context.

RESULTS

Both morphemes were found to exhibit notably contrastive marking patterns in some contexts. Each was most sensitive to a different combination of phonological influences in the verb stem and the following word.

CONCLUSIONS

These findings extend existing evidence from monolingual speakers for the influence of word-final phonological context on morpheme production to a bilingual population. Further, novel findings not yet attested in previous research support an expanded consideration of phonological context in clinical decision making and future research related to word-final morphology.

Third person singular -s in typical development and specific language impairment: Input and neighbourhood density

The purpose of this study was to examine factors promoting the use of third person singular -s by 23 children with specific language impairment (SLI) and 21 children with typical development (TD). Relative proportions of third person singular -s forms in the input (input proportion) were calculated for 25 verbs based on data from an American English corpus of child-directed speech. Neighbourhood density values were also collected for these verbs. With previously collected probes of third person singular -s use for each of these verbs, we found with logistic regression that input proportion was positively associated with the likelihood of third person singular -s use for both groups. For neighbourhood density, we found that children with SLI were more likely to inflect sparse verbs than dense verbs; density was not significantly related to inflection use for TD children. We argue that as a result of their verbs' poorly encoded phonological representations, children with SLI were less able to inflect dense verbs than sparse verbs. We recommend that clinicians be aware of the effects of input proportion and neighbourhood density to ensure that assessments are representative and that treatment success is optimal.

The Role of Frequency in Learning Morphophonological Alternations: Implications for Children With Specific Language Impairment

PURPOSE

The aim of this article was to explore how the type of allomorph (e.g., past tense buzz[d] vs. nod[əd]) influences the ability to perceive and produce grammatical morphemes in children with typical development and with specific language impairment (SLI).

METHOD

The participants were monolingual Australian English-speaking children. The SLI group included 13 participants (mean age = 5;7 [years;months]); the control group included 19 children with typical development (mean age = 5;4). Both groups performed a grammaticality judgment and elicited production task with the same set of nonce verbs in third-person singular and past tense forms.

RESULTS

Five-year-old children are still learning to generalize morphophonological patterns to novel verbs, and syllabic /əz/ and /əd/ allomorphs are significantly more challenging to produce, particularly for the SLI group. The greater phonetic content of these syllabic forms did not enhance perception.

CONCLUSIONS

Acquisition of morphophonological patterns involving low-frequency allomorphs is still underway in 5-year-old children with typical development, and it is even more protracted in SLI populations, despite these patterns being highly predictable. Children with SLI will therefore benefit from targeted intervention with low-frequency allomorphs.

Infant-directed speech reduces English-learning infants' preference for trochaic words

Over the past couple of decades, research has established that (1) infant-directed speech (IDS) facilitates speech, language, and cognitive development; and (2) infants are sensitive to the rhythmic structures in the ambient language. However, little is known about the role of IDS in infants' processing of rhythmic structures. Building on these two lines of research, whether IDS enhances infants' sensitivity to the predominant stress pattern (trochaic) in English was asked. To address this question, 9-month-old American infants were familiarized and tested with both trochaic (e.g., lazy) and iambic (e.g., cartoon) words presented in either IDS or adult-directed speech (ADS). Infants showed listening preference for the trochaic over iambic words when the speech was presented in ADS, but not in IDS. These results suggest that IDS attenuates infants' preference for trochaic stress pattern. Further acoustical analyses demonstrated that IDS provided less salient spectral cues for the contrasts between stressed and unstressed syllables in trochaic words. These findings encourage further efforts to explore the effects of IDS on language acquisition from a broader perspective.

Effects of Type of Agreement Violation and Utterance Position on the Auditory Processing of Subject-Verb Agreement: An ERP Study

Previous ERP studies have often reported two ERP components-LAN and P600-in response to subject-verb (S-V) agreement violations (e.g., the boys (*) runs). However, the latency, amplitude and scalp distribution of these components have been shown to vary depending on various experiment-related factors. One factor that has not received attention is the extent to which the relative perceptual salience related to either the utterance position (verbal inflection in utterance-medial vs. utterance-final contexts) or the type of agreement violation (errors of omission vs. errors of commission) may influence the auditory processing of S-V agreement. The lack of reports on these effects in ERP studies may be due to the fact that most studies have used the visual modality, which does not reveal acoustic information. To address this gap, we used ERPs to measure the brain activity of Australian English-speaking adults while they listened to sentences in which the S-V agreement differed by type of agreement violation and utterance position. We observed early negative and positive clusters (AN/P600 effects) for the overall grammaticality effect. Further analysis revealed that the mean amplitude and distribution of the P600 effect was only significant in contexts where the S-V agreement violation occurred utterance-finally, regardless of type of agreement violation. The mean amplitude and distribution of the negativity did not differ significantly across types of agreement violation and utterance position. These findings suggest that the increased perceptual salience of the violation in utterance final position (due to phrase-final lengthening) influenced how S-V agreement violations were processed during sentence comprehension. Implications for the functional interpretation of language-related ERPs and experimental design are discussed.

The prosodic licensing of coda consonants in early speech: interactions with vowel length

English has a word-minimality requirement that all open-class lexical items must contain at least two moras of structure, forming a bimoraic foot (Hayes, 1995).Thus, a word with either a long vowel, or a short vowel and a coda consonant, satisfies this requirement. This raises the question of when and how young children might learn this language-specific constraint, and if they would use coda consonants earlier and more reliably after short vowels compared to long vowels. To evaluate this possibility we conducted an elicited imitation experiment with 15 two-year-old Australian English-speaking children, using both perceptual and acoustic analysis. As predicted, the children produced codas more often when preceded by short vowels. The findings suggest that English-speaking two-year-olds are sensitive to language-specific lexical constraints, and are more likely to use coda consonants when prosodically required.

Syntagmatic and paradigmatic development of cochlear implanted children in comparison with normally hearing peers up to age 7

OBJECTIVE

Grammatical development is shown to be delayed in CI children. However, the literature has focussed mainly on one aspect of grammatical development, either morphology or syntax, and on standard tests instead of spontaneous speech. The aim of the present study was to compare grammatical development in the spontaneous speech of Dutch-speaking children with cochlear implants and normally hearing peers. Both syntagmatic and paradigmatic development will be assessed and compared with each other.

METHOD

Nine children with cochlear implants were followed yearly between ages 2 and 7. There was a cross-sectional control group of 10 normally hearing peers at each age. Syntactic development is measured by means of Mean Length of Utterance (MLU), morphological development by means of Mean Size of Paradigm (MSP). This last measure is relatively new in child language research.

RESULTS

MLU and MSP of children with cochlear implants lag behind that of their normally hearing peers up to age 4 and up to age 6 respectively. By age 5, CI children catch up on MSP and by age 7 they caught up on MLU.

CONCLUSION

Children with cochlear implants catch up with their normally hearing peers for both measures of syntax and morphology. However, it is shown that inflection is earlier age-appropriate than sentence length in CI children. Possible explanations for this difference in developmental pace are discussed.

Phonological and morphophonological effects on grammatical development in children with specific language impairment

BACKGROUND

Five-year-olds with specific language impairment (SLI) often struggle with mastering grammatical morphemes. It has been proposed that verbal morphology is particularly problematic in this respect. Previous research has also shown that in young typically developing children grammatical markers appear later in more phonologically challenging contexts.

AIMS

The main aim was to explore whether grammatical deficits in children with SLI are morphosyntactic in nature, or whether phonological factors also explain some of the variability in morpheme production. The analysis considered the effects of the same phonological factors on the production of three different morphemes: two verbal (past tense -ed; third-person singular -s) and one nominal morpheme (possessive -s).

METHODS & PROCEDURES

The participants were 30 children with SLI (21 boys) aged 4;6-5;11 years (mean = 5;1). The data were collected during grammar test sessions, which consisted of question/answer elicitations of target forms involving picture props. A total of 2301 items were analysed using binary logistic regression; the predictors included: (1) utterance position of the target word, (2) phonological complexity of its coda, (3) voicing of the final stem consonant, (4) syllabicity (allomorph type) and (5) participant accounting for the individual differences in the responses.

OUTCOMES & RESULTS

The results showed a robust effect of syllabicity on the correct morpheme production. Specifically, syllabic allomorphs (e.g., She dresses) were significantly more challenging than the segmental ones (e.g., He runs) for all three morphemes. The effects of other factors were observed only for a single morpheme: coda complexity and voicing helped explain variability in past tense production, and utterance position significantly affected children's performance with the possessive. The participant factor also had a significant effect, indicating high within-group variability--often observed in SLI population.

CONCLUSIONS & IMPLICATIONS

The systematic effect of syllabicity across both verbal and nominal morphemes suggests morphophonological influences in the grammatical development of children with SLI that cannot be fully explained by syntactic deficits. Poorer performance in producing syllabic allomorphs can be accounted for by much lower overall frequency of these forms, and by the 'tongue-twisting' effect of producing similar segments in succession, as in added [aedəd], washes [wɒʃəz]. Interestingly, the greater acoustic salience of the syllabic allomorphs (an extra syllable) does not enhance children's abilities to produce them. These findings suggest that the interconnections between different levels of language have a stronger effect on the grammatical development of children with SLI than might be expected. Allomorphy should, therefore, be taken into account when designing language assessments and speech therapy, ensuring that children receive sufficient practice with the entire set of allomorphic variants.

Examination of the Locus of Positional Effects on Children's Production of Plural -s: Considerations From Local and Global Speech Planning

PURPOSE

Prosodic and articulatory factors influence children's production of inflectional morphemes. For example, plural -s is produced more reliably in utterance-final compared to utterance-medial position (i.e., the positional effect), which has been attributed to the increased planning time in utterance-final position. In previous investigations of plural -s, utterance-medial plurals were followed by a stop consonant (e.g., dogsbark), inducing high articulatory complexity. We examined whether the positional effect would be observed if the utterance-medial context were simplified to a following vowel.

METHOD

An elicited imitation task was used to collect productions of plural nouns from 2-year-old children. Nouns were elicited utterance-medially and utterance-finally, with the medial plural followed by either a stressed or an unstressed vowel. Acoustic analysis was used to identify evidence of morpheme production.

RESULTS

The positional effect was absent when the morpheme was followed by a vowel (e.g., dogseat). However, it returned when the vowel-initial word contained 2 syllables (e.g., dogsarrive), suggesting that the increased processing load in the latter condition negated the facilitative effect of the easy articulatory context.

CONCLUSIONS

Children's productions of grammatical morphemes reflect a rich interaction between emerging levels of linguistic competence, raising considerations for diagnosis and rehabilitation of language disorders.

The role of sentence position, allomorph, and morpheme type on accurate use of s-related morphemes by children who are hard of hearing

PURPOSE

Production accuracy of s-related morphemes was examined in 3-year-olds with mild-to-severe hearing loss, focusing on perceptibility, articulation, and input frequency.

METHOD

Morphemes with /s/, /z/, and /ɪz/ as allomorphs (plural, possessive, third-person singular -s, and auxiliary and copula "is") were analyzed from language samples gathered from 51 children (ages: 2;10 [years;months] to 3;8) who are hard of hearing (HH), all of whom used amplification. Articulation was assessed via the Goldman-Fristoe Test of Articulation-Second Edition, and monomorphemic word final /s/ and /z/ production. Hearing was measured via better ear pure tone average, unaided Speech Intelligibility Index, and aided sensation level of speech at 4 kHz.

RESULTS

Unlike results reported for children with normal hearing, the group of children who are HH correctly produced the /ɪz/ allomorph more than /s/ and /z/ allomorphs. Relative accuracy levels for morphemes and sentence positions paralleled those of children with normal hearing. The 4-kHz sensation level scores (but not the better ear pure tone average or Speech Intelligibility Index), the Goldman-Fristoe Test of Articulation-Second Edition, and word final s/z use all predicted accuracy.

CONCLUSIONS

Both better hearing and higher articulation scores are associated with improved morpheme production, and better aided audibility in the high frequencies and word final production of s/z are particularly critical for morpheme acquisition in children who are HH.

Children's acquisition of English onset and coda /l/: articulatory evidence

PURPOSE

The goal of this study was to better understand how and when onset /l/ (leap) and coda /l/ (peel) are acquired by children by examining both the articulations involved and adults' perceptions of the produced segments.

METHOD

Twenty-five typically developing Australian English-speaking children aged 3;0 (years;months) to 7;11 participated in an elicited imitation task, during which audio, video, and lingual ultrasound images were collected. Transcribers perceptually rated audio, whereas video and ultrasound images were visually examined for the presence of adult-like articulations.

RESULTS

Data from this study establish that for Australian English-learning children, coda /l/s are acquired later than onset /l/s, and older children produce greater proportions of adultlike /l/s in both onset and coda positions, roughly following established norms for American English-speaking children. However, although perceptibility of coda /l/s was correlated with their articulations, onset /l/s were nearly uniformly perceived as adultlike despite substantial variation in the articulations used to produce them.

CONCLUSIONS

The disparity in the production and perception of children's singleton onset /l/s is linked to both physiological and phonological development. Suggestions are made for future research to tease these factors apart.

Early comprehension of the Spanish plural

Understanding how linguistic cues map to the environment is crucial for early language comprehension and may provide a way for bootstrapping and learning words. Research has suggested that learning how plural syntax maps to the perceptual environment may show a trajectory in which children first learn surrounding cues (verbs, modifiers) before a full mastery of the noun morpheme alone. The Spanish plural system of simple codas, dominated by one allomorph -s, and with redundant agreement markers, may facilitate early understanding of how plural linguistic cues map to novel referents. Two-year-old Mexican children correctly identified multiple novel object referents when multiple verbal cues in a phrase indicated plurality as well as in instances when the noun morphology in novel nouns was the only indicator of plurality. These results demonstrate Spanish-speaking children's ability to use plural noun inflectional morphology to infer novel word referents which may have implications for their word learning.

Infinitives or bare stems? Are English-speaking children defaulting to the highest-frequency form?

Young English-speaking children often produce utterances with missing 3sg -s (e.g., *He play). Since the mid 1990s, such errors have tended to be treated as Optional Infinitive (OI) errors, in which the verb is a non-finite form (e.g., Wexler, 1998; Legate & Yang, 2007). The present article reports the results of a cross-sectional elicited-production study with 22 children (aged 3;1-4;1), which investigated the possibility that at least some apparent OI errors reflect a process of defaulting to the form with the highest frequency in the input. Across 48 verbs, a significant negative correlation was observed between the proportion of 'bare' vs. 3sg -s forms in a representative input corpus and the rate of 3sg -s production. This finding suggests that, in addition to other learning mechanisms that yield such errors cross-linguistically, at least some of the OI errors produced by English-speaking children reflect a process of defaulting to a high-frequency/phonologically simple form.

Cluster reduction and compensatory lengthening in the acquisition of possessive -s

Previous research shows that two-year-olds' third person singular -s and plural -s are produced more accurately in utterance-final compared to utterance-medial position. However, only the third person singular is affected by coda complexity. This study explores these effects with possessive -s. Acoustic analysis of twelve two-year-olds' elicited imitations examined the use of simple versus complex codas (e.g. Sue's vs. Doug's ) both utterance-medially and utterance-finally. Morpheme production was surprisingly robust across contexts, though coda clusters were often simplified to a lengthened -s morpheme utterance-medially (e.g., Dou's [dɐz]). The findings raise many questions about the development of speech planning processes across populations.

The role of utterance length and position in 3-year-olds' production of third person singular -s

PURPOSE Evidence from children's spontaneous speech suggests that utterance length and utterance position may help explain why children omit grammatical morphemes in some contexts but not others. This study investigated whether increased utterance length (hence, increased grammatical complexity) adversely affects children's third person singular -s production in more controlled experimental conditions. METHOD An elicited imitation task with 12 Australian English-speaking children ages 2;9 (years;months) to 3;2 (Mage = 2;11) was conducted comparing third person singular -s production in 3-word and 5-word utterances, both utterance medially (e.g., He sits back; He sits back and swings) and utterance finally (e.g., There he sits; That's the way he sits) using a within-subjects design. Children were shown pictorial representations of each utterance on a computer and were invited to repeat 16 pseudorandomized prerecorded utterances. Acoustic analysis determined the presence/absence and duration of the third person singular morpheme. RESULTS Third person singular production was significantly lower utterance medially compared to utterance finally for the 5-word utterances and significantly lower utterance medially in the 5-word compared to 3-word utterances. CONCLUSION These results suggest that increased utterance length results in significantly lower third person singular production, but only in the more articulatorily challenging utterance-medial position. Thus, morpheme omission is greatest at the intersection of grammatical and phonological complexity.

Past tense productivity in Dutch children with and without SLI: the role of morphophonology and frequency

This study focuses on morphophonology and frequency in past tense production. It was assessed whether Dutch five- and seven-year-old typically developing (TD) children and eight-year-old children with specific language impairment (SLI) produce the correct allomorph in regular, irregular, and novel past tense formation. Type frequency of the allomorph, token frequency and phonotactic probability (PP) of the novel verb form are considered. The results showed all groups were sensitive to the phonological cue. PP did not contribute to past tense inflection of novel verbs in any of the groups, but type frequency did in all three groups. Only the seven-year-old typically developing children relied on token frequency for inflection of regulars. The findings point to an important role of phonology and frequency in past tense acquisition for both TD children and children with SLI. We discuss how the SLI performance pattern relates to theories on SLI.

Grammatical outcomes of 3- and 6-year-old children who are hard of hearing

PURPOSE

Spoken language skills of 3- and 6-year-old children who are hard of hearing (HH) were compared with those of children with normal hearing (NH).

METHOD

Language skills were measured via mean length of utterance in words (MLUw) and percent correct use of finite verb morphology in obligatory contexts based on spontaneous conversational samples gathered from 185 children (145 HH, 40 NH). Aided speech intelligibility index (SII), better-ear pure-tone average (BE-PTA), maternal education, and age of amplification were used to predict outcomes within the HH group.

RESULTS

On average, the HH group had MLUws that were 0.25-0.5 words shorter than the NH group at both ages, and they produced fewer obligatory verb morphemes. After age, aided SII and age of amplification predicted MLUw. Aided SII and BE-PTA were not interchangeable in this analysis. Age followed by either BE-PTA or aided SII best predicted verb morphology use.

CONCLUSIONS

Children who are HH lag behind their peers with NH in grammatical aspects of language. Although some children appear to catch up, more than half of the children who are HH fell below the 25th percentile. Continued monitoring of language outcomes is warranted considering that children who are HH are at increased risk for language learning difficulties.

Acoustic investigations into the later acquisition of syllabic -es plurals

PURPOSE

Children acquire /-z/ syllabic plurals (e.g., bus es) later than /-s, -z/ segmental plurals (e.g., cat s, dog s). In this study, the authors explored whether increased syllable number or segmental factors best explains poorer performance with syllabic plurals.

METHOD

An elicited imitation experiment was conducted with 14 two-year-olds involving 8 familiar disyllabic target plural nouns, half with syllabic plurals (e.g., bus → bus es) and half with segmental plurals (e.g., letter → letter s). Children saw pictures of the target items on a computer and repeated prerecorded 3-word-utterances with the target word in utterance-medial position (e.g., "The buses come") and utterance-final position (e.g., "Hear the buses"). Acoustic analysis determined the presence or absence of the plural morpheme and its duration.

RESULTS

Children had more trouble producing syllabic plurals compared with segmental plurals. Errors were especially evident in the utterance-medial position, where there was less time for the child to perceive/produce the word in the absence of phrase-final lengthening and where planning for the following word was still required.

CONCLUSIONS

The results suggested that articulatory difficulties-rather than a word length effect-explain later acquisition of syllabic plurals relative to segmental plurals. These findings have implications for the nature of syllabic plural acquisition in children with hearing impairments and specific language impairment.

Verb inflection in monolingual Dutch and sequential bilingual Turkish-Dutch children with and without SLI

Both children with specific language impairment (SLI) and children who acquire a second language (L2) make errors with verb inflection. This overlap between SLI and L2 raises the question if verb inflection can discriminate between L2 children with and without SLI. In this study we addressed this question for Dutch. The secondary goal of the study was to investigate variation in error types and error profiles across groups. Data were collected from 6-8-year-old children with SLI who acquire Dutch as their first language (L1), Dutch L1 children with a typical development (TD), Dutch L2 children with SLI, and Dutch L1 TD children who were on average 2 years younger. An experimental elicitation task was employed that tested use of verb inflection; context (3SG, 3PL) was manipulated and word order and verb type were controlled. Accuracy analyses revealed effects of impairment in both L1 and L2 children with SLI. However, individual variation indicated that there is no specific error profile for SLI. Verb inflection use as measured in our study discriminated fairly well in the L1 group but classification was less accurate in the L2 group. Between-group differences emerged furthermore for certain types of errors, but all groups also showed considerable variation in errors and there was not a specific error profile that distinguished SLI from TD.

Durational cues to fricative codas in 2-year-olds' American English: voicing and morphemic factors

In the process of phonological development, fricatives are generally assumed to be later acquired than stops. However, most of the observational work on which this claim is based has concerned itself with word-initial onset consonants; little is known about how and when fricatives are mastered in word-final coda position (e.g., nose). This is all the more critical in a language like English, where word-final fricatives often carry important morphological information (e.g., toes, goes). This study examines the development of duration cues to the voicing feature contrast in coda fricatives, using longitudinal spontaneous speech data from CVC words (e.g., noise vs face) produced by three children (1;6-2;6 years) and six mothers. Results show that the children were remarkably adult-like in the use of duration cues to voicing contrasts in fricatives even in this early age range. Furthermore the children, like the mothers, had longer frication noise durations for morphemic compared to non-morphemic fricatives (e.g., toes vs nose) when these segments occurred in utterance-final position. These results suggest that although children's fricatives tend to be overall longer and more voiced compared to those of adults, the voicing and morphological contrasts for fricative codas are acquired early in production.

Verb inflection in German-learning children with typical and atypical language acquisition: the impact of subsyllabic frequencies

Previous research has shown that high phonotactic frequencies facilitate the production of regularly inflected verbs in English-learning children with specific language impairment (SLI) but not with typical development (TD). We asked whether this finding can be replicated for German, a language with a much more complex inflectional verb paradigm than English. Using an elicitation task, the production of inflected nonce verb forms (3(rd) person singular with -t suffix) with either high- or low-frequency subsyllables was tested in sixteen German-learning children with SLI (ages 4;1-5;1), sixteen TD-children matched for chronological age (CA) and fourteen TD-children matched for verbal age (VA) (ages 3;0-3;11). The findings revealed that children with SLI, but not CA- or VA-children, showed differential performance between the two types of verbs, producing more inflectional errors when the verb forms resulted in low-frequency subsyllables than when they resulted in high-frequency subsyllables, replicating the results from English-learning children.

Segmental and positional effects on children's coda production: comparing evidence from perceptual judgments and acoustic analysis

Children's early productions are highly variable. Findings from children's early productions of grammatical morphemes indicate that some of the variability is systematically related to segmental and phonological factors. Here, we extend these findings by assessing 2-year-olds' production of non-morphemic codas using both listener decisions and acoustic analyses. Results showed that utterance position and coda manner influence perception, in that more stop codas were perceived utterance-finally compared to utterance-medially but fricative codas were perceived equally across utterance positions. Acoustic analyses showed some convergence to listeners' perception in that there were more cues associated with stops utterance-finally compared to utterance-medially. However, there was some divergence between the two methods in that acoustic cues to coda segments were also present in the majority of cases where a coda was not perceived. These findings provide insight into both the nature of children's emerging phonological representations and the effectiveness of coda transcription across segment types.

The Role of Phonology in Children's Acquisition of the Plural

The correct use of an affix, such as the English plural suffix, may reflect mastery of a morphological process but it may also depend on children's syntactic, semantic and phonological abilities. The present paper reports a set of experiments in support of this latter view, specifically focusing on the importance of the phonological make-up of plural forms for both production and comprehension. In Experiments 1 and 2 plural productions were elicited from eighty two-year-old children for nouns with codas with varying phonological properties. The results provide evidence that production of the plural morpheme is partly governed by the complexity of the coda and its sonority. Experiments 3 and 4 show that these constraints on codas also hold for comprehension as well, suggesting this effect is not simply articulatory, but also impacts the morphophonology of the plural.

Acoustic evidence for positional and complexity effects on children's production of plural -s

PURPOSE

Some variability in children's early productions of grammatical morphemes reflects phonological factors. For example, production of 3rd person singular -s is increased in utterance-final versus utterance-medial position and in simple versus cluster codas (e.g., sees vs. hits). Understanding the factors that govern such variability is an important step toward modeling developmental processes. In this study, the authors examined the generality of these effects by determining whether position and coda complexity influence production of plural -s, which phonologically manifests the same as 3rd person singular -s.

METHOD

The authors used an elicited imitation task to examine the speech of 16 two-year-olds. Eight plural nouns (half contained simple codas, half contained cluster codas) were elicited utterance-medially and utterance-finally. Acoustic analysis of each noun was used to identify acoustic cues associated with coda production.

RESULTS

Results showed that plural production was more robust in utterance-final versus utterance-medial position but equally robust in simple versus cluster codas.

CONCLUSIONS

These findings extend positional effects on morpheme production to plural -s. An effect of coda complexity was not observed for plural but was observed for 3rd person singular, which raises the possibility that the morphological representation proper influences the degree to which phonological factors affect morpheme production.

Sentence-position effects on children's perception and production of English third person singular -s

PURPOSE

Two-year-olds produce third person singular -s more accurately on verbs in sentence-final position as compared with verbs in sentence-medial position. This study was designed to determine whether these sentence-position effects can be explained by perceptual factors.

METHOD

For this purpose, the authors compared 22- and 27-month-olds' perception and elicited production of third person singular -s in sentence-medial versus-final position. The authors assessed perception by measuring looking/listening times to a 1-screen display of a cartoon paired with a grammatical versus an ungrammatical sentence (e.g., She eats now vs. She eat now).

RESULTS

Children at both ages demonstrated sensitivity to the presence/absence of this inflectional morpheme in sentence-final, but not sentence-medial, position. Children were also more accurate at producing third person singular -s sentence finally, and production accuracy was predicted by vocabulary measures as well as by performance on the perception task.

CONCLUSIONS

These results indicate that children's more accurate production of third person singular -s in sentence-final position cannot be explained by articulatory factors alone but that perceptual factors play an important role in accounting for early patterns of production. The findings also indicate that perception and production of inflectional morphemes may be more closely related than previously thought.

Interactions between lexical and phonological development: cross-linguistic and contextual considerations--a commentary on Stoel-Gammon's 'Relationships between lexical and phonological development in young children'

Stoel-Gammon (this issue) provides a welcome addition to the phonological acquisition literature, bringing together insights from long-standing and more recent research to address the relationship between the developing phonological system and the developing lexicon. A growing literature on children's early use of words across languages and phonological contexts provides additional insight into the nature of the interactions between phonological and lexical development, suggesting that learners' knowledge and connection of the two may develop much earlier than often thought. This commentary highlights some of these exciting results from recent cross-linguistic research on development between the ages of 1 and 3.

Longitudinal development of phonology and morphology in children with late-identified mild-moderate sensorineural hearing loss

OBJECTIVE

Studies of language development in children with mild-moderate hearing loss are relatively rare. Longitudinal studies of children with late-identified hearing loss are relevant for determining how a period of unaided mild-moderate hearing loss impacts development. In recent years, newborn hearing screening programs have effectively reduced the ages of identification for most children with permanent hearing loss. However, some children continue to be identified late, and research is needed to guide management decisions. Furthermore, studies of this group may help to discern whether language normalizes after intervention and/or whether certain aspects of language might be vulnerable to persistent delays. The current study examines the impact of late identification and reduced audibility on speech and language outcomes via a longitudinal study of four children with mild-moderate sensorineural hearing loss.

DESIGN

Longitudinal outcomes of four children with late-identified mild-moderate sensorineural hearing loss were studied using standardized measures and language sampling procedures from at or near the point of identification (28 to 41 mos) through 84 mos of age. The children with hearing loss were compared with 10 age-matched children with normal hearing on a majority of the measures through 60 mos of age. Spontaneous language samples were collected from mother-child interaction sessions recorded at consistent intervals in a laboratory-based play setting. Transcripts were analyzed using computer-based procedures (Systematic Analysis of Language Transcripts) and the Index of Productive Syntax. Possible influences of audibility were explored by examining the onset and productive use of a set of verb tense markers and by monitoring the children's accuracy in the use of morphological endings. Phonological samples at baseline were transcribed and analyzed using Computerized Profiling.

RESULTS

At entry to the study, the four children with hearing loss demonstrated language delays with pronounced delays in phonological development. Three of the four children demonstrated rapid progress with development and interventions and performed within the average range on standardized speech and language measures compared with age-matched children by 60 mos of age. However, persistent differences from children with normal hearing were observed in the areas of morphosyntax, speech intelligibility in conversation, and production of fricatives. Children with mild-moderate hearing loss demonstrated later than typical emergence of certain verb tense markers, which may be related to reduced or inconsistent audibility.

CONCLUSIONS

The results of this study suggest that early communication delays will resolve for children with late-identified, mild-moderate hearing loss, given appropriate amplification and intervention services. A positive result is that three of four children demonstrated normalization of broad language behaviors by 60 mos of age, despite significant delays at baseline. However, these children are at risk for persistent delays in phonology at the conversational level and for accuracy in use of morphological markers. The ways in which reduced auditory experiences and audibility may contribute to these delays are explored along with implications for evaluation of outcomes.