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…

It is well attested that high socio-economic status (SES) is associated with larger vocabulary size estimates in young children. This has led to growing interest in identifying associations and mechanisms that may contribute to this relationship. In this study, parent-child reading behaviors were investigated in relation to vocabulary size in a…

In this article, we present an analysis of the complexity of grammatical constraints and their impact on early language acquisition of inflectional morphemes in Malayalam. We use the natural speech production data of two monolingual children acquiring Malayalam between the ages 1;9-2;10 and 2;3-3;0 and three bilingual children acquiring…

Most words spoken to infants are produced in larger units, such as clauses, phrases, and sentences. As such, language learners must recognize words amidst the words that surround them. However, the phonetic forms of words change based on surrounding context. Here, we investigate the effects of a common source of phonetic change--phonological…

Code-switching is a common phenomenon in bilingual communities, but little is known about bilingual parents' code-switching when speaking to their infants. In a pre-registered study, we identified instances of code-switching in day-long at-home audio recordings of 21 French-English bilingual families in Montreal, Canada, who provided recordings…

Infants attune to their native language during the first two years of life, as attested by decreases in the processing of nonnative phonological sounds and reductions in the range of possible sounds accepted as labels for native words. The present study shows that French-learning infants aged 1;8 can learn new words in an unfamiliar language,…

Vulnerability of morphosyntactic production, including grammatical aspect, has been identified in at least some children with autism spectrum disorder (ASD) exposed to typologically different languages. However, Tovar et al. (2015) found strengths in comprehending grammatical aspect in English-exposed children with ASD, suggesting that the…

Infants are sensitive to statistical regularities (i.e., transitional probabilities, or TPs) relevant to segmenting words in fluent speech. However, there is debate about whether tracking TPs results in representations of possible words. Infants show preferential learning of sequences with high TPs (HTPs) as object labels relative to those with…

Previous papers in these pages have dealt empirically with the child's first words, the child's first imitations, and the use of yes/no and wh-questions with infants. In this study, we touch on all these issues, but attempt to place them in a systemic-functional language framework and a cultural-historical learning one. First, we deal with some of…

Early trilingual development is an excellent testing ground for input reduction effects on acquisition outcomes. This article reports a study investigating input-outcome relations in a child Leo in Hong Kong, who was addressed to in Mandarin, Cantonese and later also in English by caretakers through 'one caretaker-one language' and 'one day-one…

To evaluate which features of spoken language aid infant word learning, a corpus of infant-directed speech (M. R. Brent & J. M. Siskind, 2001) was characterized on several linguistic dimensions and statistically related to the infants' vocabulary outcomes word by word. Comprehension (at 12 and 15 months) and production (15 months) were…

In a simultaneous bilingual education, there are many factors that can affect its success, primarily the age of the child and socio-cognitive elements. This phenomenon can be initially studied in the first lexical productions of either language in a child. The present study focuses on the early lexical developments of a child, who lives in the…

Over the past several decades, researchers have discovered a great deal of information about the processes underlying language acquisition. From as early as they can be studied, infants are sensitive to the nuances of native-language sound structure. Similarly, infants are attuned to the visual and conceptual structure of their environments…

Infants have remarkable abilities to learn several languages. However, phonological acquisition in bilingual infants appears to vary depending on the phonetic similarities or differences of their two native languages. Many studies suggest that learning contrasts with different realizations in the two languages (e.g., the /p/, /t/, /k/ stops have…

The first years of life represent a unique window of opportunity for foreign language learning. However, key questions are: How much and what kind of foreign language exposure is needed to ignite learning? We conducted a foreign language (English) intervention in four public Infant Education Centers in Madrid, Spain. Intervention children (N =…