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…

Purpose: This article focuses on toddlers' revisions of the sentence subject and tests the hypothesis that subject diversity (i.e., the number of different subjects produced) increases the probability of subject revision. Method: One-hour language samples were collected from 61 children (32 girls) at 27 months. Spontaneously produced, active…

The purpose of this study was to determine if children acquire grammatical case as a unified system or in a piecemeal fashion. In English language acquisition, many children make developmental errors in marking case on subject position pronouns (e.g., "Me" do it, "Him" like it). It is unknown whether children who produce…

This article investigates the relationship between third person singular present tense agreement morphemes, copula "is" and verb-"s", at 2;00 and 2;03. Language samples from 60 children at 2;00 were analyzed for the productivity of copula "is" as measured by the number of different morphemes preceding "is"…

Purpose: This follow-up study examined whether a parent intervention that increased the diversity of lexical noun phrase subjects in parent input and accelerated children's sentence diversity (Hadley et al., 2017) had indirect benefits on tense/agreement (T/A) morphemes in parent input and children's spontaneous speech. Method: Differences in…

Purpose: The goals of this study were to quantify longitudinal expectations for verb lexicon growth and to determine whether verb lexicon measures were better predictors of later grammatical outcomes than noun lexicon measures. Method: Longitudinal parent-report measures from the MacArthur-Bates Communicative Development Inventory (Fenson et al.,…

Purpose: The relatedness of tense morphemes in the language of children younger than 3 years of age is a matter of controversy. Generativist accounts predict that the morphemes will be related, whereas usage-based accounts predict the absence of relationships. This study focused on the increasing productivity of the 5 morphemes in the tense…

Purpose: The authors of this study investigated the validity of tense and agreement productivity (TAP) scoring in diverse sentence frames obtained during conversational language sampling as an alternative measure of finiteness for use with young children. Method: Longitudinal language samples were used to model TAP growth from 21 to 30 months of…

Purpose: The current study used an intervention design to test the hypothesis that parent input sentences with diverse lexical noun phrase (NP) subjects would accelerate growth in children's sentence diversity. Method: Child growth in third person sentence diversity was modeled from 21-30 months (n = 38) in conversational language samples obtained…

Purpose: Evidence for tense marking in child-directed speech varies both across languages (Guasti, 2002; Legate & Yang, 2007) and across speakers of a single language (Hadley, Rispoli, Fitzgerald, & Bahnsen, 2011). The purpose of this study was to understand how parent interaction styles and register use overlap with the tense-marking…

Examines the relationship between third-person-singular subject pronoun case and agreement, focusing on the hypothesis that these two grammatical subsystems develop together. Twenty-nine children between ages 2 and 4 years of age were each audiotaped for approximately two hours playing and interacting with their primary caregivers. (Author/VWL)

This study explored the relationship between sentence disruptions and the length and complexity of sentences spoken by 26 typical children developing grammar. For most children, disrupted sentences tended to be longer and more complex than fluent sentences and the magnitude of the differences in length and complexity was positively correlated with…

This longitudinal case study describes an anomalous error produced by a child with specific language impairment (SLI), MM, whose language development was documented from ages 3 through 7 years. Twelve spontaneous language samples were analyzed. Across nine language samples MM produced the phonetic sequence heard in the [there/their/they're homonym…

A study tested the hypothesis that if, for the 2-year-old, the transitive/intransitive distinction functions to signal differences in the conceptualization of actions, the child's sentence production should show a relationship between sentence frame and (1) locus of change animacy and (2) the child's expectations concerning an action's outcome.…