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…

A strong predictor of children's language is performance on non-word repetition (NWR) tasks. However, the basis of this relationship remains unknown. Some suggest that NWR tasks measure phonological working memory, which then affects language growth. Others argue that children's knowledge of language/language experience affects NWR performance. A…

Young children can exploit the syntactic context of a novel word to narrow down its probable meaning. This is "syntactic bootstrapping." A learner that uses syntactic bootstrapping to foster lexical acquisition must first have identified the semantic information that a syntactic context provides. Based on the "semantic seed…

Why do infants learn some words earlier than others? Many theories of early word learning focus on explaining how infants map labels onto concrete objects. However, words that are more abstract than object nouns, such as "uh-oh," "hi," "more," "up," and "all-gone," are typically among the first to…

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,…

This study evaluates the potential for incidentally learning early reading vocabulary through the extensive viewing (EV) of children's movies/television with subtitles. Recent research has investigated how much exposure to important vocabulary EV and extensive reading (ER) provides. Investigations compute the number of repetitions of target…

Children learn language by listening to speech from caregivers around them. However, the type and quantity of speech input that children are exposed to change throughout early childhood in ways that are poorly understood due to the small samples (few participants, limited hours of observation) typically available in developmental psychology. Here…

Children need to learn the demands of their native language in the early vocabulary development phase. In this dynamic process, parental multimodal input may shape neurodevelopmental trajectories while also being tailored by child-related factors. Moving beyond typically characterized group profiles, in this article, we synthesize growing evidence…

In order for children to understand and reason about the world in an adult-like fashion, they need to learn that conceptual categories are organized in a hierarchical fashion (e.g., a dog is also an animal). While children learn from their first-hand observation of the world, social knowledge transmission via language can also play an important…

Word learning is typically studied as a problem in which children need to learn a single meaning for a new word. And by most theories, children's learning is itself guided by the assumption that a new word will have only one meaning. However, the majority of words in languages are polysemous, carrying multiple related and distinct meanings. Here,…

What makes a word easy to learn? Early-learned words are frequent and tend to name concrete referents. But words typically do not occur in isolation. Some words are predictable from their contexts; others are less so. Here, we investigate whether predictability relates to when children start producing different words (age of acquisition; AoA). We…

What is vision's role in driving early word production? To answer this, we assessed parent-report vocabulary questionnaires administered to congenitally blind children (N = 40, Mean age = 24 months [R: 7-57 months]) and compared the size and contents of their productive vocabulary to those of a large normative sample of sighted children (N =…

This dissertation articulates and defends a view about linguistic competence called 'variabilism'. According to variabilism, the epistemic demands of full linguistic competence vary in a particular way. More specifically, variabilism holds that different individual lexical application conditions (individually essential metaphysical ways of being…

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…

Multisyllabic words constitute a large portion of children's vocabulary. However, the relationship between phonological neighborhood density and English multisyllabic word learning is poorly understood. We examine this link in three, four and six year old children using a corpus-based approach. While we were able to replicate the well-accepted…