Early vocabulary development benefits from diverse lexical exposures within children's language environment. However, the influence of lexical diversity on children as they enter middle childhood and are exposed to multimodal language inputs remains unclear. This study evaluates global and local aspects of lexical diversity in three…

In a seminal study, Cameron-Faulkner et al. made two important observations about utterance-level constructions in English child-directed speech (CDS). First, they observed that canonical in/transitive sentences are surprisingly infrequent in child-direct speech (given that SVO word order is often thought to play a key role in the acquisition of…

Purpose: The Language ENvironment Analysis (LENA) technology uses automated speech processing (ASP) algorithms to estimate counts such as total adult words and child vocalizations, which helps understand children's early language environment. This ASP has been validated in North American English and other languages in predominantly monolingual…

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…

Purpose: Autistic individuals often face challenges perceiving and expressing emotions, potentially stemming from differences in speech prosody. Here we explore how autism diagnoses between groups, and measures of social competence within groups may be related to, first, children's speech characteristics (both prosodic features and amount of…

Purpose: Talkers adapt their speech according to the demands of their listeners and the communicative context, enhancing the properties of the signal (pitch, intensity) and/or properties of the code (enhancement of phonemic contrasts). This study asked how mothers adapt their child-directed speech (CDS) in ways that might serve the immediate goals…

Causation is a core feature of human cognition and language. How children learn about intricate causal meanings is yet unresolved. Here, we focus on how children learn verbs that express causation. Such verbs, known as lexical causatives (e.g., break and raise), lack explicit morphosyntactic markers indicating causation, thus requiring that the…

This study focuses on parental use of parentese: the acoustically exaggerated, clear, and higher-pitched speech produced by adults across cultures when they address infants. While previous research shows that parentese enhances language learning and processing, it is still unclear what drives the variability in the amount of parental parentese…

In early childhood centres, decontextualised talk is often associated with literacy activities. In this study, however, we investigated toddler-educator conversations across various activities with a focus on those about topics that were not related to the immediate context. We examined the communicative purposes and linguistic features of these…

We investigated the effect of part of speech adoption on the utterance length of Mandarin-speaking children. A total of 209 typically developing Taiwanese children aged 3-6 years participated in the study. They included 90 boys and 119 girls recruited from preschools in Miaoli City, New Taipei City, and Taipei City. We collected children's…

Purpose: The purpose of the present study was to examine whether there is a listening preference for child-directed speech (CDS) over backward speech in moderate-preterm infants (MPIs). Method: Eighteen MPIs of gestational age of 32.0 weeks (range: 32-34.06 weeks), chronological age of 8.09 months, and maturation age of 6.48 months served as the…

This study investigates the speech rate of Cypriot Greek-speaking children with developmental language disorder (DLD) as well as the effect of age and gender. The participants were 16 children with DLD ages 4 years 11 months to 8 years 1 month and 22 children with typical language development (TLD) ages 4 years 5 months to 8 years 7 months. Both…

The acquisition of quantifiers is a central topic in cognitive science. The present study investigated the emergence, frequency, and non-target-like production of the universal quantifiers "all," "every," and "each" in child English from a linguistic perspective, based on the data from longitudinal naturalistic…

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…

The first stage of combinatorial speech is better described as variable than uniform. Talk of variants obscures two different aspects of language (knowledge and use) and two different aspects of language development -- acquisition of the grammar (competence) and deployment of the grammar in speaking and listening (performance). Null subjects and…