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…

Ambridge's proposal cannot account for the most basic observations about phonological patterns in human languages. Outside of the earliest stages of phonological production by toddlers, the phonological systems of speakers/learners exhibit internal behaviours that point to the representation and processing of inter-related units ranging in size…

Spoken words vary phonetically along a number of dimensions, such as duration, pitch, and vowel quality. Much of this variation is associated with social factors like the dialect, age, or gender of the speaker -- a type of variation termed 'socio-indexical'. Traditional theories of speech perception have seen this socio-indexical variation as a…

This study took a novel approach to understanding the role of language in spatial development by combining approaches from spatial language and gesture research. It analyzed forty-three 4.5- to 6-year-old's speech and gesture production during explanations of reasoning behind performance on Spatial Analogies and Children's Mental Transformation…

Metadiscourse, a linguistic means that is used in the production and organization of ideas, is vital in achieving successful communication. In language studies, metadiscourse in writing and speaking have been disparately investigated, where the former received more attention than the latter. Thus, the present study analyzes metadiscourse in the…

Across languages, lexical items specific to infant-directed speech (i.e., 'baby-talk words') are characterized by a preponderance of onomatopoeia (or highly iconic words), diminutives, and reduplication. These lexical characteristics may help infants discover the referential nature of words, identify word referents, and segment fluent speech into…

The words in children's language learning environments are strongly predictive of cognitive development and school achievement. But how do we measure language environments and do so at the scale of the many words that children hear day in, day out? The quantity and quality of words in a child's input are typically measured in terms of total amount…

In phonetics research, language alternation--including code switching (speaker-initiated) and cued switching (researcher-prompted)--can be used as a tool to investigate various aspects of speech production and perception in bilingual or multilingual speakers (Bullock & Toribio, 2009a). Studies on the production of voice onset time (VOT) during…

Contrastive focus, conveyed by prosodic cues, marks important information. Studies have shown that 6-year-olds learning English and Japanese can use contrastive focus during online sentence comprehension: focus used in a "contrastive context" facilitates the identification of a target referent (speeding up processing), whereas focus used…

This study presents a cross-sectional and longitudinal analysis of how 108 high school students in English as a foreign language (EFL) classrooms enhanced the comprehensibility of their second language (L2) speech according to different motivation, emotion, and experience profiles. Students' learning patterns were primarily associated with their…

Cognitive factors have been recognised as important in the interpreting process, but whether they could serve as valid components of interpreting aptitude still awaits further investigation. This study explores the predictive value of cognitive fluency in the simultaneous interpreting (SI) performance of trainee interpreters. Cognitive fluency…

Scholars have argued for the inclusion of different spoken varieties of English in high-stakes listening tests to better represent the global use of English. However, doing so may introduce additional construct-irrelevant variance due to accent familiarity and the shared first language (L1) advantage, which could threaten test fairness. However,…

This study addresses the social-cognitive interactions that occur in code-switching and integrates social and cognitive factors from a usage-based perspective. It investigates code-switching in two different interaction modes -- speech and writing -- to consider not only the influence of social factors (social networks and attitudes) but also the…

Variability in the form of article (i.e., a and the) omissions and stressing has been attributed to a mismatch between first (L1) and second language (L2) prosodic and syntactic structures. An overlap between the L1 and L2 systems, on the other hand, is expected to contribute to native-like article productions. This case study aims to explore the…

In this dissertation, I investigated how cognitive resources as well as formal, and informal language experience impact language learning in two studies. In the first study (Chapter 2), I examined the learning of Spanish grammatical gender by Chinese international students who were studying abroad in the US. The goal of that study was to uncover…