Aspectual and mood morphology are vulnerable domains in adult heritage speakers. This paper investigates the root of such vulnerability within the domain of Turkish evidentiality system by comparing 20 second-generation adult and 20 school-age child Turkish heritage speakers to 20 first-generation immigrants (main input providers for child…

This paper revisits the longstanding observation that children produce modal verbs (e.g., must, could) with their root meanings (e.g., abilities, obligations) by age 2, typically a year or more earlier than with their epistemic meanings (e.g., inferences). Established explanations for this "Epistemic Gap" argue that epistemic language…

The "wanna" facts are a classic Poverty of Stimulus (PoS) problem: "Wanna" is grammatical in certain contexts ("Who do you want PRO to play with?") but not others ("Who do you want who[strikethrough] to play with you?"). On a standard analysis, "contraction" to "wanna" is blocked by some…

I review the classic literature in generative grammar and Marr's three-level program for cognitive science to defend the Evaluation Metric as a psychological theory of language learning. Focusing on well-established facts of language variation, change, and use, I argue that optimal statistical principles embodied in Bayesian inference models are…

Generative approaches to language have long recognized the natural link between theories of knowledge representation and theories of knowledge acquisition. The basic idea is that the knowledge representations provided by Universal Grammar enable children to acquire language as reliably as they do because these representations highlight the…

Using an observational task followed by an experimental task with an Intermodal Preferential Looking Paradigm, we examined the effect of input on children's acquisition of class extension rules by investigating the relationship between the amount of polysemous noun-verb pairs in French-speaking 2-year-olds' input and both their spontaneous…

Two recent proposals link the use of nonagreeing "don't" to the Root Infinitive (RI) Stage. Guasti & Rizzi (2002) argue for a misset parameter involving how agreement is spelled out. Schütze (2010) proposes that Infl is underspecified in child language and that "do" surfaces to support the contracted clitic/affix…

Researchers have long debated the mechanisms underlying the learning of syntactic structure. Of significant interest has been the fact that passive constructions appear to be learned earlier in Sesotho than English. This paper provides a comprehensive, quantitative analysis of the passive input Sesotho-speaking children hear, how it differs from…