The first stage of combinatorial speech is better described as variable than uniform. Talk of variants obscures two different aspects of language (knowledge and use) and two different aspects of language development -- acquisition of the grammar (competence) and deployment of the grammar in speaking and listening (performance). Null subjects and…

Natural languages contain systematic relationships between verb meaning and verb argument structure. Artificial language learning studies typically remove those relationships and instead pair verb meanings randomly with structures. Adult participants in such studies can detect statistical regularities associated with words in these languages and…

This study investigates the role of emotional linguistic input in learning novel words with abstract and concrete denotations. It is widely accepted that concrete words are processed more easily than abstract ones. Several theories of vocabulary acquisition additionally propose a critical role of sensorimotor and emotional information during novel…

Maternal scaffolding and four-year-old children's linguistic skills were examined during toy play. Participants were 21 American-English monolingual and 21 Thai monolingual mother-child dyads. Results revealed cross-cultural differences in conversation styles between the two groups. American dyads adopted a high-elaborative style relative to Thai…

Languages differ in how they encode causal events, placing greater or lesser emphasis on the agent or patient of the action. Little is known about how these preferences emerge and the relative influence of cognitive biases and language-specific input at different stages in development. In these studies, we investigated the emergence of sentence…

Efficient language use involves the capacity to flexibly adjust to varied pronunciations of words. Although children can contend with some accent variability before their second birthday, it is currently unclear when and how this ability reaches its mature state. In a series of five experiments, we examine the developmental trajectory of toddlers'…

In many languages, significant numbers of words are used in more than one grammatical category; English, in particular, has many words that can be used as both nouns and verbs. Such "ambicategoricality" potentially poses problems for children trying to learn the grammatical properties of words and has been used to argue against the logical…