Infants begin to produce abstract "math" words -- such as numbers (e.g., "two"), spatial terms (e.g., "down"), and magnitude words (e.g., "more") -- during their second postnatal year. Math words, as all words, are likely learned in the home setting during interactions with caregivers. However, everyday…

In low- and middle-income countries, urbanization has spurred the expansion of peri-urban communities, or urban communities of formerly rural residents with low socioeconomic status. The growth of these communities offers researchers an opportunity to measure the associations between the level of urbanization and the home language environment…

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…

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…

Bilingual infants acquire languages in a variety of language environments. Some caregivers follow a one-person-one-language approach in an attempt to not "confuse" their child. However, the central assumption that infants can keep track of what language a person speaks has not been tested. In two studies, we tested whether bilingual and…

This paper invites us to reconsider our usual understanding of infancy, no longer as something that passes but as "infantia." The Latin word "infantia," which is not easy to translate, means a lack of speech, a lack of eloquence, and also infancy, babyhood, and dumbness. Drawing on Barbara Cassin's works on the untranslatables,…

Parents are often a good source of information, introducing children to how the world around them is described and explained in terms of cause-and-effect relations. Parents also vary in their speech, and these variations can predict children's later language skills. Being born preterm might be related to such parent-child interactions. The present…

Latino families should be fully supported to accomplish their goals for the bilingual development and school success of their children. Unfortunately, they often encounter misinformation and negative messages regarding early bilingual development, specifically the belief that young children are "confused" if they grow up with two…

Using a habituation paradigm with a three-switch design, the present study investigated whether 20-month-old French-learning infants use noun and verb morphosyntactic cues to learn novel words in dynamic events differentially when both the agent and the action interpretations are possible. Of particular interest was whether infants' initial…

Linguistic interactions between parents and their children are frequently studied to investigate how children acquire language. From observations, researchers have identified interaction strategies that foster children's language development. In turn, interventions to support children's early language skills employ styles of interaction derived…

What is the function of babbling in language learning? We examined the structure of parental speech as a function of contingency on infants' non-cry prelinguistic vocalizations. We analyzed several acoustic and linguistic measures of caregivers' speech. Contingent speech was less lexically diverse and shorter in utterance length than…

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.…

Infants learn nouns during object-naming events--moments when caregivers name the object of infants' play (e.g., ball as infant holds a ball). Do caregivers also label the actions of infants' play (e.g., roll as infant rolls a ball)? We investigated connections between mothers' verb inputs and infants' actions. We video-recorded 32 infant-mother…

This study examines the quantity and quality of child-directed speech across household activities in a socioeconomically diverse sample of Argentinian Spanish-speaking children, an understudied population. Thirty children (mean: 14.3 months) and their families were audio-recorded for four hours. The middle two hours were transcribed and analysed…

This study focuses on adult responses to children's verb uses, the information they provide, and how they change over time. We analyzed longitudinal samples from four children acquiring Hebrew (age-range: 1;4-2;5; child verb-forms = 8,337). All child verbs were coded for inflectional category, and for whether and how adults responded to them. Our…