Sentence Diversity in Early Language Development: Recommendations for Target Selection and Progress Monitoring

The Contribution of Noun and Verb Lexicon Sizes to Later Grammatical Outcomes in Mandarin-Speaking Children With Cochlear Implants

PURPOSE

The present study evaluated the applicability of the sentence-focused framework to Mandarin-speaking children with cochlear implants (CIs) by examining the relative contribution of receptive/expressive noun and verb lexicon sizes to later grammatical complexity.

METHOD

Participants were 51 Mandarin-speaking children who received cochlear implantation before 30 months of age. At 12 months after CI activation, parents were asked to endorse words that their child could understand only or understand and say using the infant version of the Early Vocabulary Inventory. At 24 months after CI activation, parents were asked to endorse the grammatical structures that their children were able to say using the Grammatical Complexity subtest in the Mandarin Communicative Development Inventory-Taiwan. Children's receptive/expressive noun and verb lexicon sizes and grammatical complexity scores were computed from these parent checklists.

RESULTS

Correlational analyses showed that children's receptive/expressive noun and verb lexicon sizes at 12 months after CI activation were all highly correlated with their grammatical complexity scores at 24 months after CI activation (ρs = .52-.63, ps < .001). Regression analyses further revealed that verb lexicon sizes at 12 months after CI activation outweighed noun lexicon sizes in accounting for grammatical complexity at 24 months after CI activation.

CONCLUSIONS

Our findings supported the prediction of the sentence-focused framework. Emphasizing the role of verbs in early intervention has the potential to enhance grammatical outcomes in Mandarin-speaking children with CIs.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.26129044.

Exploring grammatical development in children aged 2;6 to 7: a novel approach using elicited production

The assessment of children's grammatical skills is a crucial component of diagnosing language disorders. Elicited production is a commonly used method for obtaining data on a child's productive language abilities. We introduce a new instrument developed as part of the third edition of a standardised test battery for German. This instrument utilises elicited production, wherein participants describe coloured pictures depicting everyday situations, in order to generate four test scores: mean length of utterances, completeness of utterances, and two grammar scores comprising relevant target structures. The construction of the grammar scores was inspired by the Index of Productive Syntax (IPSyn), modified for German and computerised. The detailed results provide a comprehensive profile of a child's syntactic and morphological strengths and weaknesses. Analysis of data collected from 348 monolingual German children who formed part of the norming sample, aged between 2;6 and 6;11 years of age, revealed age-related changes in these scores. Additionally, the age range was determined for both grammatical milestones and 'red flags', which may indicate potential problems in language development. In conclusion, the newly developed, time-efficient instrument allows for a detailed assessment of grammatical skills, identification of potential intervention targets, and facilitates various research objectives.

Varying Syntax to Enhance Verb-Focused Intervention for 30-Month-Olds With Language Delay: A Concurrent Multiple Baseline Design

PURPOSE

The purpose of this study is to determine if 2.5-year-olds with language delay would learn verbs (spill) when presented with varying syntactic structure ("The woman is spilling the milk"/"The milk is spilling"; milk = patient or theme) in a therapeutic context. Children with language delay have proportionally small inventories of verbs, which limits expressive language development. Children who have typical language development learn verbs more robustly when presented with alternating arguments than with a single argument structure.

METHOD

Three toddlers with expressive language delay (29-30 months of age) participated in a verb-focused treatment study using a concurrent multiple baseline design. Participants were shown action videos accompanied by sentences with varied argument structure for each target verb. To assess learning pre- and posttreatment, participants were asked to demonstrate actions corresponding to each verb.

RESULTS

Visual inspection and tau analyses reveal significant posttreatment gains of target verbs taught with varying argument structures.

CONCLUSIONS

Our results indicate that learning verbs with high variability of argument roles may facilitate a strong link between lexical representations of verbs and their syntactic structures. Using argument structure variability to teach verbs as an intervention strategy has great potential and should be tested further in larger group studies.

Natural language acquisition and gestalt language processing: A critical analysis of their application to autism and speech language therapy. AUTISM & DEVELOPMENTAL LANGUAGE IMPAIRMENTS 2024;9:23969415241249944. [PMID: 38784430 PMCID: PMC11113044 DOI: 10.1177/23969415241249944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background and Aim

Recently, there has been a lot of interest surrounding the term gestalt language processor (GLP) which is associated with Natural Language Acquisition (NLA): a protocol intended to support the language development of autistic people. In NLA, delayed echolalia is presumed raw source material that GLPs use to acquire language in a stage-like progression from delayed echolalia to spontaneous speech. The aim of this article is to evaluate NLA in light of relevant literatures to allow scrutiny of NLA claims.

Main contributions

First, we review the notion of gestalt language and situate it in the broader literature on language styles to update understanding of its significance. We then review the links from gestalt language processing to autism and identify definitional and conceptual problems and clarify the construct 'episodic memory'. We discuss the 'raw material view of delayed echolalia' and identify theoretical and empirical shortcomings. Finally, we review Blanc's language stages and their accompanying assessment and language support recommendations and challenge their validity.

Conclusions & Implications

The term 'gestalt language processor' is definitionally and conceptually troubled, the assertion that autistic people are GLPs is misleading and unhelpful, and evidence is lacking that GLP represents a legitimate clinical entity. The theoretical basis of NLA lacks empirical support. NLA stages are implausible and their accompanying assessment and support recommendations lack justification. We recommend the use of alternate, individualized, theoretically-sound, evidence-based, neurodiversity-affirming supports that are sensitive and responsive to the heterogeneity that defines autism.

Parent Responsivity, Language Input, and the Development of Simple Sentences

This study explored responsive and linguistic parent input features during parent-child interactions and investigated how four input categories related to children's production of diverse, simple sentences. Of primary interest was parent use of responsive, simple declarative input sentences. Responsive and linguistic features of parent input to 20 typically developing toddlers at 1;9 were coded during play in a laboratory playroom, then classified into four input categories: responsive, declarative, responsive declarative, and neither responsive nor simple declarative. The percentage of each input category was related to child sentence diversity at 2;6 using Spearman correlations. Parent use of responsive declarative and declarative utterances were both rare. Responsive input was positively correlated with child sentence diversity, and the neither category was negatively correlated with child sentence diversity. The findings provide new support for the importance of balanced conversational turns. Implications for defining both how input is delivered and its linguistic content are discussed.

Noun and Verb Lexicons Differentially Predict Later Grammatical Development in Mandarin-Speaking Children With and Without Late Language Emergence

PURPOSE

The current investigation evaluated the extent to which early noun, verb, and adjective lexicon sizes predicted later grammatical outcomes in Mandarin-speaking children with and without late language emergence (LLE) using a parent report.

METHOD

In Study 1, the parents of 24 Mandarin-speaking children with typical language filled out the toddler version of Mandarin-Chinese Communicative Development Inventory-Taiwan (MCDI-T) when these children were 24 and 36 months old. In Study 2, the parents of 23 children with LLE completed the same form when these children were 24, 36, and 48 months old. Noun, verb, and adjective lexicon sizes and grammatical complexity scores were computed from the MCDI-T form for each child.

RESULTS

Study 1 showed that verb lexicon size, but not noun or adjective lexicon size, at 24 months predicted grammatical complexity scores at 36 months for children with typical language. Study 2 revealed that noun lexicon size, but not verb or adjective lexicon size, at 24 months predicted grammatical complexity scores at 36 months for children with LLE. Noun lexicon size at 36 months was also the only significant predictor for grammatical complexity scores at 48 months in children with LLE.

CONCLUSIONS

Noun and verb lexicon size differentially predicted later grammatical outcomes in young Mandarin-speaking children with and without LLE. The finding suggested that children with LLE may have approached grammatical learning differently from their typical peers due to the small verb lexicon size in the early phase of language 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.

Sentence Diversity in Spanish-English Bilingual Toddlers

PURPOSE

There remain few available tools to assess language development in Spanish-English dual language learner (DLL) toddlers in the United States. Of interest is the development of early sentences as children move from producing single words to producing multiword utterances. This study is the first to extend sentence diversity to the context of Spanish-English DLLs by describing development from 24 to 30 months of age in children with and without language delays (LDs).

METHOD

Spontaneous language samples were collected from Spanish-dominant DLL children and their mothers as they were observed during a free-play interaction. Existing sentence diversity protocols were adapted for the DLL context to describe children's flexibility in combining subjects and verbs to form utterances in Spanish and English.

RESULTS

Children maintained an accurate separation in their grammars for subject-verb combinations in Spanish versus English. There was an overwhelming preference for Spanish subject-verb combinations with null subjects. The emergence of sentence diversity distinguished children with and without early LD unlike the emergence of word combinations.

CONCLUSIONS

Consistent with prior research, findings showed that DLLs did not confuse grammatical structures across languages. Instead, they showed a differential pattern of results in each language, such that the strongest grammatical skills were evinced first in the dominant language. Sentence diversity shows promise for assessment and progress monitoring in Spanish-English DLLs in the United States.

Feature-rich multiplex lexical networks reveal mental strategies of early language learning

Knowledge in the human mind exhibits a dualistic vector/network nature. Modelling words as vectors is key to natural language processing, whereas networks of word associations can map the nature of semantic memory. We reconcile these paradigms-fragmented across linguistics, psychology and computer science-by introducing FEature-Rich MUltiplex LEXical (FERMULEX) networks. This novel framework merges structural similarities in networks and vector features of words, which can be combined or explored independently. Similarities model heterogenous word associations across semantic/syntactic/phonological aspects of knowledge. Words are enriched with multi-dimensional feature embeddings including frequency, age of acquisition, length and polysemy. These aspects enable unprecedented explorations of cognitive knowledge. Through CHILDES data, we use FERMULEX networks to model normative language acquisition by 1000 toddlers between 18 and 30 months. Similarities and embeddings capture word homophily via conformity, which measures assortative mixing via distance and features. Conformity unearths a language kernel of frequent/polysemous/short nouns and verbs key for basic sentence production, supporting recent evidence of children's syntactic constructs emerging at 30 months. This kernel is invisible to network core-detection and feature-only clustering: It emerges from the dual vector/network nature of words. Our quantitative analysis reveals two key strategies in early word learning. Modelling word acquisition as random walks on FERMULEX topology, we highlight non-uniform filling of communicative developmental inventories (CDIs). Biased random walkers lead to accurate (75%), precise (55%) and partially well-recalled (34%) predictions of early word learning in CDIs, providing quantitative support to previous empirical findings and developmental theories.

Disentangling the Grammar of 3- to 6-Year-Old Dutch Children With a Developmental Language Disorder

PURPOSE

Children with a developmental language disorder (DLD) are often delayed in their grammatical development. This is suggested to be the most important characteristic and clinical marker of DLD. However, it is unknown if this assumption is valid for young children, in the earliest stages of grammatical development. For this reason, this study investigates the complexity, diversity, and accuracy of the grammatical repertoires of 3- to 6-year-old Dutch children with DLD, in comparison to that of typically developing (TD) children matched on grammatical level.

METHOD

Language samples of 59 children (29 children with DLD and 30 TD children) were analyzed using multiple measures of grammatical complexity, diversity, and accuracy. The TD children and children with DLD were language-matched on their grammatical development using the levels of the Dutch version of the Language Assessment, Remediation, and Screening Procedure, the Taal Analyse Remediëring en Screening Procedure (TARSP; Schlichting, 2017). Thus, the children with DLD were significantly older than the TD children (respectively DLD age range: 2;7-5;4 [years;months], M _age = 4;1; and TD age range: 2;0-3;9, M _age = 2;9).

RESULTS

The results show that children with DLD are comparable to language-matched TD children in their grammatical accuracy and diversity, but that they produce less complex utterances.

CONCLUSIONS

The results indicate that children with DLD lag behind in their grammatical complexity as compared to language-matched TD children. The results also suggest that grammatical TARSP level is not sufficiently informative for selecting treatment goals. Instead, the results underline the importance of conducting language sample analyses, with special reference to the complexity of the utterances of a child with DLD.

Lexicogrammatical skills in 2-year-old children with and without repaired cleft palate

The purpose of the current research was to compare the lexical-grammatical skills of two-year-old children with and without repaired cleft palate (CP), accounting for the effect of variables such as vocabulary size at 18 months of age, maternal education level, and gender. Participants included 52 children with CP and 25 typically developing (TD) children. The CDI-WS was employed to measure vocabulary and grammatical skills. Significant differences were observed between the CP and TD groups with respect to the number of words, word forms (irregular nouns and verbs), word endings (overuse of plural (-s) and past tense (-ed) markers), the mean number of morphemes in their three longest utterances (M3L), and sentence complexity. In addition, compared to TD children, significantly smaller proportions of children with CP were observed to use words to talk about past and future events or use words to talk about an absent object. The difference between the CP and TD groups in terms of the size of vocabulary at 24 months of age remained statistically significant in the multivariable model. Among all predictors, the size of vocabulary at 18 months of age was identified as the most robust precursor of lexical and grammatical skills at 24 months of age. Gender was identified as a predictor of the M3L measure as an index for syntactic ability.

Aided Language Measures: Establishing Observer Agreement for Communicators in Early Language Phases

PURPOSE

Although many valid, reliable, and developmentally sensitive measures exist to monitor the language gains of children who rely on spoken language to communicate, the same is not true for graphic symbol communicators. This study is a first step in developing such measures by examining the interobserver agreement (IOA) and within-observer agreement of 13 measures designed to monitor the language progress of children who use aided augmentative and alternative communication (AAC). These measures are based on the Graphic Symbol Utterance and Sentence Development Framework (Binger et al., 2020) and are hypothesized to capture various phases of graphic symbol communication.

METHOD

Four graduate student observers coded 13 measures across 57 different play-based sessions of children with Down syndrome ages 3;0-5;11 (years;months). For IOA, sessions were coded by two different observers. For within-observer agreement, all sessions were recoded by the same coders. Corpus-level analyses were completed to characterize the nature of the samples (e.g., average mean length of utterance for the samples). IOA and within-observer agreement were examined for each utterance.

RESULTS

Across all observers and measures, acceptable levels of IOA and within-observer agreement were achieved, with most measures yielding relatively high levels of agreement. Some differences were noted across measures, with the less experienced coders demonstrating less agreement on select measures.

CONCLUSIONS

Results provide initial evidence that many measures based on the Graphic Symbol Utterance and Sentence Development Framework can be reliably coded. These findings are a first step in developing psychometrically sound measures to monitor the expressive language progress of children who use AAC.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19601551.

Caregiver Language Input Supports Sentence Diversity in Young Children With Autism Spectrum Disorder

PURPOSE

Sentence diversity is a measure of early language development that has yet to be applied to individuals with autism spectrum disorder (ASD). The primary aim of this study was to identify whether children with ASD show change in sentence diversity over 6 months of treatment with Naturalistic Developmental Behavioral Intervention (NDBI). The secondary aim was to examine possible predictors of changes in children's sentence diversity, including caregiver use of NDBI strategies, naturally occurring instances of caregiver Toy Talk, and child characteristics.

METHOD

Fifty children with ASD (ages 2-4 years) and their caregivers, who were receiving NDBI, engaged in two 10-min video-recorded play interactions, 6 months apart. Child speech was transcribed and coded for sentence diversity. Caregiver input was transcribed and coded for naturally occurring Toy Talk. Zero-inflated negative binomial mixed models were used to explore predictors of change in child sentence diversity.

RESULTS

Children's sentence diversity improved over time. Changes in caregiver NDBI strategy use and caregiver baseline Toy Talk were significant predictors of changes in sentence diversity, as were baseline age, nonverbal ratio IQ, and child sex. Additionally, a significant interaction of caregiver baseline Toy Talk and change in caregiver NDBI strategies emerged; the effect of caregiver baseline Toy Talk on children's sentence diversity change was stronger when NDBI strategy use improved.

CONCLUSIONS

Sentence diversity is a developmentally sensitive measure of language development in ASD. NDBI strategies that facilitate reciprocal social communication, combined with input composed of declarative sentences with noun or third-person pronoun subjects, may provide optimal support for children's sentence development.

Using Animated Action Scenes to Remotely Assess Sentence Diversity in Toddlers

Although language samples are child-friendly and well-suited for obtaining global measures of language production, structured protocols have the potential to elicit many different exemplars of language structures in a shorter amount of time. We created a structured elicitation protocol, the Sentence Diversity Priming Task (SDPT), to efficiently assess sentence diversity in toddlers via video chat platforms. Sentence diversity is operationalized as the number of different subject–verb combinations in active declarative sentences. The task is presented as an animated picture book, with parents serving as the child's primary partner during administration. In this article, we provide the rationale for assessing sentence diversity, describe the task, and present preliminary analyses of compliance and developmental associations for 32 typically developing toddlers, 30–35 months old, with average language abilities. The preliminary findings suggest that the SDPT is an engaging task that holds toddlers' attention, reveals robust individual differences in their ability to produce sentences, is positively correlated with parent-reported language measures, and has the potential for assessing children's language growth over time. Finally, recommendations and tips for developing and remotely administering the protocol are provided, with an emphasis on encouraging parent involvement and increasing toddler compliance.

Language Intervention Isn't Just Spoken: Assessment and Treatment of a Deaf Signing Child With Specific Language Impairment

Purpose This case study describes the language evaluation and treatment of a 5-year-old boy, Lucas, who is Deaf, uses American Sign Language (ASL), and presented with a language disorder despite native access to ASL and no additional diagnosis that would explain the language difficulties. Method Lucas participated in an evaluation where his nonverbal IQ, fine motor, and receptive/expressive language skills were assessed. Language assessment included both formal and informal evaluation procedures. Language intervention was delivered across 7 weeks through focused stimulation. Results Evaluation findings supported diagnosis of a language disorder unexplained by other factors. Visual analysis revealed an improvement in some behaviors targeted during intervention (i.e., number of different verbs and pronouns), but not others. In addition, descriptive analysis indicated qualitative improvement in Lucas' language production. Parent satisfaction survey results showed a high level of satisfaction with therapy progress, in addition to a belief that Lucas improved in language areas targeted. Conclusions This study adds to the growing body of literature that unexplained language disorders in signed languages exist and provides preliminary evidence for positive outcomes from language intervention for a Deaf signing child. The case described can inform professionals who work with Deaf signing children (e.g., speech-language pathologists, teachers of the Deaf, and parents of Deaf children) and serve as a potential starting point in evaluation and treatment of signed language disorders. Supplemental Material https://doi.org/10.23641/asha.16725601.

Marking of Tense and Agreement in Language Samples by Children With and Without Specific Language Impairment in African American English and Southern White English: Evaluation of Scoring Approaches and Cut Scores Across Structures

Purpose As follow-up to a previous study of probes, we evaluated the marking of tense and agreement (T/A) in language samples by children with specific language impairment (SLI) and typically developing controls in African American English (AAE) and Southern White English (SWE) while also examining the clinical utility of different scoring approaches and cut scores across structures. Method The samples came from 70 AAE- and 36 SWE-speaking kindergartners, evenly divided between the SLI and typically developing groups. The structures were past tense, verbal -s, auxiliary BE present, and auxiliary BE past. The scoring approaches were unmodified, modified, and strategic; these approaches varied in the scoring of forms classified as nonmainstream and other. The cut scores were dialect-universal and dialect-specific. Results Although low numbers of some forms limited the analyses, the results generally supported those previously found for the probes. The children produced a large and diverse inventory of mainstream and nonmainstream T/A forms within the samples; strategic scoring led to the greatest differences between the clinical groups while reducing effects of the children's dialects; and dialect-specific cut scores resulted in better clinical classification accuracies, with measures of past tense leading to the highest levels of classification accuracy. Conclusions For children with SLI, the findings contribute to studies that call for a paradigm shift in how children's T/A deficits are assessed and treated across dialects. A comparison of findings from the samples and probes indicates that probes may be the better task for identifying T/A deficits in children with SLI in AAE and SWE. Supplemental Material https://doi.org/10.23641/asha.13564709.

Exploring Sentence Diversity at the Boundary of Typical and Impaired Language Abilities

Purpose This review article summarizes programmatic research on sentence diversity in toddlers developing language typically and explores developmental patterns of sentence diversity in toddlers at risk for specific language impairment. Method The first half of this review article presents a sentence-focused approach to language assessment and intervention and reviews findings from empirical studies of sentence diversity. In the second half, subject and verb diversity in three simple sentence types are explored in an archival database of toddlers with varying levels of grammatical outcomes at 36 months of age: low average, mild/moderate delay, and severe delay. Results Descriptive findings from the archival database replicated previous developmental patterns. All toddlers with low-average language abilities produced diverse simple sentences by 30 months of age and exhibited greater sentence diversity with first-person I-subjects before third-person subjects. Third-person subject diversity emerged in a developmental sequence, increasing in one-argument copula contexts and one-argument subject-verb sentences before two-argument subject-verb-object sentences. This developmental pattern held across all three outcome groups. Third-person subjects were least diverse for children with severe grammatical delays and were absent in all sentence contexts for two children with severe delays at 36 months. Conclusions Sentence diversity increases gradually and expands in predictable patterns. Understanding these developmental patterns may help identify and treat children who display unexpected difficulty combining different subjects and verbs in flexible ways. Supplemental Material and Presentation Video https://doi.org/10.23641/asha.12915320.

Tracking Early Sentence-Building Progress in Graphic Symbol Communication

Purpose As is the case with children who rely on spoken language, speech-language pathologists must support and track the expressive language development of children with complex communication needs who use graphic symbols to communicate. This research note presents a framework of the progression of expressive English sentence development using graphic symbols and introduces possible approaches for measuring and analyzing graphic symbol use. Method Current issues in measuring graphic symbol utterances are explored, and a range of measures designed to analyze individual graphic symbol utterances as well as larger samples of utterances are presented. Results Both the Graphic Symbol Utterance and Sentence Development Framework and suggested measures are based on years of graphic symbol intervention research, including two large ongoing research studies of preschoolers with severe speech impairments. Our framework adapts the work of Hadley (2014) to depict expressive language progression from early symbol combinations to childlike and adultlike sentences and highlights developmental patterns unique to graphic symbol productions. Adaptations of existing measures (such as mean length of utterance) as well as measures unique to graphic symbol analyses are presented and discussed. Conclusion To accurately track changes in early graphic symbol utterance growth and complexity, a multidimensional approach, which includes analyses such as symbol relevance, word class diversity, and lexical diversity, is recommended.

Individual and Developmental Differences in Distributional Learning

Purpose

This study examined whether children and adults with developmental language disorder (DLD) could use distributional information in an artificial language to learn about grammatical category membership similarly to their typically developing (TD) peers and whether developmental differences existed within and between DLD and TD groups.

Method

Sixteen children ages 7-9 with DLD, 26 age-matched TD children, 17 college students with DLD, and 17 TD college students participated in this task. We used an artificial grammar learning paradigm in which participants had to use knowledge of category membership to determine the acceptability of test items that they had not heard during a training phase.

Results

Individuals with DLD performed similarly to TD peers in distinguishing grammatical from ungrammatical combinations, with no differences between age groups. The order in which items were heard at test differentially affected child versus adult participants and showed a relation with attention and phonological working memory as well.

Conclusion

Differences in ratings between grammatical and ungrammatical items in this task suggest that individuals with DLD can form grammatical categories from novel input and more broadly use distributional information. Differences in order effects suggest a developmental timeline for sensitivity to updating distributional information.

The Sequential Unfolding of First Phase Syntax: Tutorial and Applications to Development

Purpose This tutorial is an introduction to first phase syntax (FPS; Ramchand, 2008 ). FPS provides a new, cross-linguistically motivated perspective on clause internal structure. A new sequence of syntactic development is proposed based on FPS with 4 levels of complexity: (0) verb particles and adjectives in the 1-word stage, (1) semantic relations of entity + location/attribution, (2) intransitive structures encoding change of location/state, and (3) transitive sentences with an internal argument that changes state/location and an external, causer argument. A novel prediction of this framework is that a Level 2 structure emerges earlier than a Level 3 structure. Method Archival longitudinal data of 15 children (8 boys) were selected to test the proposed developmental sequence. The 15 children's data were drawn from the DeKalb corpora ( Rispoli, Hadley, & Holt, 2008 , 2009 ) and Champaign corpora ( Hadley, Rispoli, Holt, Fitzgerald, & Bahnsen, 2014 ), selected because their mean lengths of utterance did not exceed 2.54 at age 2;6 (years;months). One-hour language samples taken every 3 months from 1;9 to 2;6 were searched for Level 1-3 structures. The diversity of the internal argument was tracked across levels. Results Average argument diversity shifted across levels over the period of 1;9-2;6. At 2;0, argument diversity was highest for Level 1; at 2;3, diversity was highest for Level 2; and at 2;6, it was highest for Level 3. Paired-samples t test revealed that, at 2;3, argument diversity in Level 2 was significantly higher than that in Level 3. Conclusion This developmental application of FPS provides a theoretical framework for a developmentally ordered sequence of syntactic goals and treatment targets for children struggling with the acquisition of syntax.

Let's Be Explicit About the Psycholinguistic Bases of Developmental Measures: A Response to Leonard, Haebig, Deevy, and Brown (2017)

PURPOSE

The purpose of this letter is to clarify the psycholinguistic underpinnings of the tense marker total and tense agreement productivity score and to extend the discussion of when composite diversity and productivity measures are best used.

CONCLUSION

We encourage the use of composite diversity and productivity measures when assessing grammar early in development, but we discourage the use of composite accuracy measures until children demonstrate emergence of diverse tense/agreement morphemes across a sufficient number of low-frequency sentence frames.