Codeswitching is a common feature of bilingual language practices, yet its impact on word learning is poorly understood. Critically, processing costs associated with codeswitching may extend to learning. Moreover, verbs tend to be more difficult to learn than nouns, and the challenges of learning verbs could compound with processing costs…

Purpose: Prior work has found that "late talkers" (LTs) as a group continue to demonstrate lower language and reading outcomes compared to their typically developing (TD) peers even into young adulthood. Others identified that children diagnosed with developmental language disorder (DLD) show difficulties later with theory of mind (ToM)…

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…

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…

The present study examines the mechanisms of lexical case acquisition in Russian by two-to-five-year-old Russian monolingual (n = 54) and Russian-English bilingual children (n = 38). Participants performed a picture-based sentence completion task. Sentences were constructed to elicit production of real Russian words (n = 24) and nonce words (n =…

Most deaf children have hearing parents who do not know a sign language at birth and are at risk of limited language input during early childhood. Studying these children as they learn a sign language has revealed that timing of first-language exposure critically shapes language outcomes. But the input deaf children receive in their first language…

The dissertation presents a pioneering investigation into child speech among Bikolano children. It aims to address the underdescription and underdocumentation of Child Bikol as spoken in the Philippines. Bikol, an Austronesian macrolanguage, often coexists with more dominant languages, making Bikolano children both emergent multilinguals and…

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…

Second language (L2) grammar learning is difficult. Two frameworks--the psycholinguistic lexical bottleneck hypothesis and the neurocognitive declarative/procedural model--predict that faster L2 lexical processing should facilitate L2 incidental grammar learning. We tested these predictions in a pretest-posttest syntactic adaptation study of…

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…

The current study set out to examine to what degree age of acquisition (AOA), defined as a learner's first intensive exposure to a second language (L2) environment, mediates the final state of postpubertal, spoken vocabulary attainment. In Study 1, spontaneous speech samples were elicited from experienced Japanese users of English (n = 41) using…

Sociolinguistic variation (SLV) entails that language is affected by social context (i.e. register, pragmatics). Interest in the acquisition of sociolinguistic variation in a second language (L2-SLV), as a key component of communicative competence, has grown exponentially over the past thirty years (Geeslin & Long, 2014). Researchers have…

This tutorial offers speech-language pathologists (SLPs) an opportunity to consider the theoretical constructs of language acquisition theory and the multifactorial determinants that can impinge on the language acquisition process for children with complex communication needs. The system of constraints observed through the lens of optimality…

This study aimed to adapt and validate the Word Complexity Measure (WCM) for Persian-speaking toddlers. The WCM is a tool for assessing phonological complexity, originally proposed by Stoel-Gammon. The study was conducted in two phases: (1) adapting the WCM parameters to the Persian language and (2) conducting a validation study with 60…

We investigated age-related decline in adult learning of Dutch as an additional language (Ln) in speaking, writing, listening, and reading proficiency test scores for 56,024 adult immigrants with 50 L1s who came to the Netherlands for study or work. Performance for all four language skills turned out to decline monotonically after an age of…