Research on "parentese," the acoustically exaggerated, slower, and higher-pitched speech directed toward infants, has mostly focused on maternal contributions, although it has long been known that fathers also produce parentese. Given recent societal changes in family dynamics, it is necessary to revise these mother-centered models of…

This dissertation investigates the wide-ranging implications of a simple fact: language unfolds over time. Whether as cognitive symbols in our minds, or as their physical realization in the world, if linguistic computations are not made over transient and shifting information as it occurs, they cannot be made at all. This dissertation explores the…

One of the fundamental questions in the field of language acquisition is a learnability problem, which considers how learners acquire certain aspects of language which are not directly provided in the input or whose referents are not readily observable. This dissertation investigates Japanese children's acquisition of various linguistic phenomena,…

Recent studies have accumulated to suggest that children, akin to adults, exhibit a processing advantage for formulaic language (e.g. "save energy") over novel language (e.g. "sell energy"), as well as sensitivity to phrase frequencies. The majority of these studies are based on formulaic sequences in their canonical form. In…

This dissertation investigates when and how children figure out the force of modals, that is, when and how they learn that "can/might" express possibility, whereas must/have to express necessity. Learning modal force raises a logical "Subset Problem": given that necessity entails possibility, what prevents learners from…

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…

We investigated whether children's inhibitory control (IC) is associated with their ability to produce irregular past tense verb forms as well as learn from corrective feedback following overregularization errors. Forty-eight 3;6 to 4;5 year old children were tested on the irregular past tense and provided with adult corrective input via models of…

The present study investigated the role of morphosyntactic information in the acquisition of transitive and intransitive verb argument structures (VAS) in the Japanese language, which allows massive omissions of arguments and case markers. In particular, we investigated how the 'variation sets' proposed by Küntay and Slobin work in Japanese.…

Words that describe sensory perception give insight into how language mediates human experience, and the acquisition of these words is one way to examine how we learn to categorize and communicate sensation. We examine the differential predictions of the typological prevalence hypothesis and embodiment hypothesis regarding the acquisition of…

Complex systems of inflectional morphology provide a useful testing ground for input-based language acquisition theories. Two analyses were performed on a high-density (12%) naturalistic sample of two Polish-English children's (2;0 and 3;11) and their parents' use of Polish noun inflection: first, each child's use of inflectional affixes and their…

The well-known sampling limitation of most longitudinal corpus data can be even more consequential in the study of morphosyntactic variation in child language. An analysis of caregiver input suggests that variable use in overlapping contexts may be hard to find by solely relying on corpus data collected under the sampling procedures that are…

The aim of the paper is to present the results of a research project called 'Tell Me', conducted from October 2018 to March 2020. The project focused on Bengali children living in Venice, Italy, and aimed to describe (1) children's languages in the home environment and at school; (2) the quality and quantity of input they receive in every language…

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…

We analysed both structural and functional aspects of sentences containing the four adverbials "after", "before", "because", and "if" in two dense corpora of parent-child interactions from two British English-acquiring children (2;00-4;07). In comparing mothers' and children's usage we separate out the…

This study investigated the feasibility of a vocabulary-based teacher intervention to increase preschool teachers' production of complement clauses (e.g. "I wonder if we can put the monkey in the tree") in teacher-children play interactions. Using a multiple baseline across participants design we measured the impact of an intervention…