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: 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.,…

It is by now well established that toddlers use the linguistic context in which a new word--and particularly a new verb--appears to discover aspects of its meaning. But what aspects of the linguistic context are most useful? To begin to investigate this, we ask how 2-year-olds use two sources of linguistic information that are known to be useful…

To acquire the meanings of verbs, toddlers make use of the surrounding linguistic information. For example, 2-year-olds successfully acquire novel transitive verbs that appear in semantically rich frames containing content nouns ("The boy is gonna pilk a balloon"), but they have difficulty with pronominal frames ("He is gonna pilk…

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…