As children gradually master grammatical rules, they often go through a period of producing form-meaning associations that were not observed in the input. For example, 2- to 3-year-old English-learning children use the bare form of verbs in settings that require obligatory past tense meaning while already starting to produce the grammatical…

All accounts of language acquisition agree that, by around age 4, children's knowledge of grammatical constructions is abstract, rather than tied solely to individual lexical items. The aim of the present research was to investigate, focusing on the passive, whether children's and adults' performance is additionally semantically constrained,…

Does knowledge of language transfer across language modalities? For example, can speakers who have had no sign language experience spontaneously project grammatical principles of English to American Sign Language (ASL) "signs"? To address this question, here, we explore a grammatical illusion. Using spoken language, we first show that a…

Becoming productive with grammatical categories is a gradual process in children's language development. Here, we investigated this transition process by focusing on Turkish causatives. Previous research examining spontaneous and elicited production of Turkish causatives with familiar verbs attested the onset and early stages of productivity at…

Children with developmental language disorder (DLD) have significant deficits in language ability that cannot be attributed to neurological damage, hearing impairment, or intellectual disability. The symptoms displayed by children with DLD differ across languages. In English, DLD is often marked by severe difficulties acquiring verb inflection.…

Inflectional affixes expressing the same grammatical category (e.g., subject agreement) tend to appear in the same morphological position in the word. We hypothesize that this cross-linguistic tendency toward "category clustering" is at least partly the result of a learning bias, which facilitates the transmission of morphology from one…

This study adjudicates between two opposing accounts of morphological productivity, using English past-tense as its test case. The single-route model (e.g., Bybee & Moder, 1983) posits that both regular and irregular past-tense forms are generated by analogy across stored exemplars in associative memory. In contrast, the dual-route model…

Across languages of the world, some grammatical patterns have been argued to be more common than expected by chance. These are sometimes referred to as (statistical) "language universals." One such universal is the correlation between constituent order freedom and the presence of a case system in a language. Here, we explore whether this…

This article reports on a series of 5 analyses of spontaneous production of verbal inflection (tense and person-number agreement) by 2-year-olds acquiring French as a native language. A formal analysis of the qualitative and quantitative results is developed using the unique resources of Optimality Theory (OT; Prince & Smolensky, 2004). It is…