Many children grow up hearing multiple languages, learning words in each. How does the number of languages being learned affect multilinguals' vocabulary development? In a pre-registered study, we compared productive vocabularies of bilingual (n = 170) and trilingual (n = 20) toddlers aged 17-33 months growing up in a bilingual community where…

Sometime before their second birthday, many children have a period of rapid expressive vocabulary growth called the vocabulary spurt. Theories of the underlying mechanisms differ: Accumulator models emphasize the accumulation of experience with words over time to yield a spurtlike pattern, while cognitive models attribute the spurt to cognitive…

Vocabulary size is a crucial early indicator of language development, for both monolingual and bilingual children. Assessing vocabulary in bilingual children is complex because they learn words in two languages, and there remains significant controversy about how to best measure their vocabulary size, especially in relation to monolinguals. This…

Despite the fact that in most communities interaction occurs between the child and multiple speakers, most previous research on input to children focused on input from mothers. We annotated recordings of Sesotho-learning toddlers living in non-industrial Lesotho in South Africa, and French-learning toddlers living in urban regions in France. We…

Infants are able to use the contexts in which familiar words appear to guide their inferences about the syntactic category of novel words (e.g. 'This is a' + 'dax' -> dax = object). The current study examined whether 18-month-old infants can rapidly adapt these expectations by tracking the distribution of syntactic structures in their input. In…

Purpose: This study examines the influence of lexical and phonological factors on expressive lexicon size in 40 French-speaking children tested longitudinally from 22 to 48 months. The factors include those based on the lexical and phonological properties of words in the children's lexicons (phonetic complexity, word length, neighborhood density…

Maternal input addressed to children after an early hospitalization (EH) was longitudinally compared to maternal input directed to typically developing children (TD), at 6, 9, 12, 18 and 24 months of age. The data were analyzed with the CHILDES tools for (a) word-tokens (b) word-types (c) Mean Length of Utterances (MLU) and (d) questions in which…

This is the first large-scale study of resources as a form of "language management" -- that is, a way of influencing children's language practices. We introduce the distinction between child-directed resources (i.e. those providing parents with opportunities to engage with their children in the languages they are transmitting) and…

This paper examines the acquisition of demonstratives (e.g., "that," "there") from a cross-linguistic perspective. Although demonstratives are often said to play a crucial role in L1 acquisition, there is little systematic research on this topic. Using extensive corpus data of spontaneous child speech, the paper investigates…

Successful word recognition requires that listeners attend to differences that are phonemic in the language while also remaining flexible to the variation introduced by different voices and accents. Previous work has demonstrated that American-English-learning 19-month-olds are able to balance these demands: although one-off one-feature…

Previous research suggests that toddlers can rely on distributional cues in the input to track adjacent and nonadjacent grammatical dependencies. It remains unclear whether toddlers understand the hierarchical phrase structures that determine the corresponding grammatical dependencies. We addressed this question by testing toddlers on two…

We investigate bilingual children's perception of assimilations, i.e. phonological rules by which a consonant at a word edge adopts a phonological feature of a neighboring consonant. For instance, English has place assimilation (e.g., "green" is pronounced with a final [m] in "green pen"), while French has voicing assimilation…

Previous research suggests that English monolingual children and adults can use speech disfluencies (e.g., "uh") to predict that a speaker will name a novel object. To understand the origins of this ability, we tested 48 32-month-old children (monolingual English, monolingual French, bilingual English-French; Study 1) and 16 adults…

This paper explores the connection between nurses' multilingual beliefs and their advice on multilingual parenting to families with young children. Data was gathered through video-stimulated reflection dialogues with 11 nurses employed at infant welfare clinics in Belgium. Our analysis disclosed two salient counter topics regarding participants'…

We examined French-learning toddlers' sensitivity to Subject-Verb agreement with conjoined subjects. In French, a conjoined NP triggers plural agreement even when made up of individual singular NPs. Processing of this infrequent structure in the input (see Corpus Analyses) requires going beyond surface patterns of non-adjacent dependencies to…