Previous research shows that infants of parents who are more likely to engage in socially contingent interactions with them tend to have larger vocabularies. An open question is "how" social contingency facilitates vocabulary growth. One possibility is that parents who speak in response to their infants more often produce larger…

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…

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…

Child-directed language can support language learning, but how? We addressed two questions: (1) how caregivers prosodically modulated their speech as a function of word familiarity (known or unknown to the child) and accessibility of referent (visually present or absent from the immediate environment); (2) whether such modulations affect…

Children acquire language embedded within the rich social context of interaction. This paper reports on a longitudinal study investigating the developmental relationship between conversational turn-taking and vocabulary growth in English-acquiring children (N = 122) followed between 9 and 24 months. Daylong audio recordings obtained every 3 months…

Background: Early in development, caregivers' object labelling contributes to children's word learning. Language development is a bi-directional process, and differences in joint engagement (JE) and language among children with developmental disabilities such as autism spectrum disorder (ASD) may provide caregivers varying contexts and…

Many Western industrialized nations have high levels of ethnic diversity but to date there are very few studies which investigate prelinguistic and early language development in infants from ethnic minority backgrounds. This study tracked the development of infant communicative gestures from 10 to 12 months (n = 59) in three culturally distinct…

Do parents fine-tune the MLU of utterances with a particular word as the word is on the verge of appearing in the child's production? We analyzed a corpus of spontaneous interactions of 30 dyads. The children were in the initial stages of their lexical development, and the parents' utterances containing the words the children eventually acquired…

Fourteen-month-old infants are unable to link minimal pair nonsense words with novel objects (Stager & Werker, 1997). Might an adult's productions in a word learning context support minimal pair word-object association in these infants? We recorded a mother interacting with her 24-month-old son, and with her 5-month-old son, producing nonsense…

While it is established that parental "wh"-questions, as a high-quality language input, are associated with child language outcome, less is known about the role of children's "wh"-questions in their language development. This study examines whether children's "wh"-questions during a dinnertime conversation are…

When engaged in conversation, both parents and children tend to re-use words that their partner has just said. This study explored whether proportions of maternal and/or child utterances that overlapped in content with what their partner had just said contributed to growth in mean length of utterance (MLU), developmental sentence score, and…

Individuals with sex chromosome trisomies (SCTs) have an increased risk of language delays and impairments. However, there are only a few data relative to their language development in early childhood. The present study aimed to investigate the preverbal skills shown by a group of 8-month-old children with SCTs to assess the presence of a possible…

Background: An association between social disadvantage and early language development is commonly reported in the literature, but less attention has been paid to the way that different aspects of social disadvantage affect both expressive and receptive language in the first 2 years of life. Aims: To examine the contributions of gender, parental…

The contribution of parent input to children's subsequent expressive verb diversity was explored in twenty typically developing toddlers with small verb lexicons. Child developmental factors and parent input measures (i.e. verb quantity, verb diversity, and verb-related structural cues) at age 1;9 were examined as potential predictors of…

Researchers have consistently found a link between the quality of early parent-child book-reading interactions and children's language skill. Two aspects of quality (level of abstraction and utterance function) were examined simultaneously in the current study to further refine our understanding of how parents' talk during shared reading predicts…