This longitudinal study tracked ten L1 English-speaking learners' acquisition of Spanish voiceless stops /ptk/ by measuring their voice onset time (VOT) over an academic year in two distinct contexts of learning. Living in a Spanish-speaking dorm, participants in the experimental group experienced a "domestic partial-immersion," in which…

Traditional research into individual differences (ID) in second language (L2) learning is based on group studies with the implicit assumption that findings can be generalized to the individual. In this article, we challenge this view. We argue that L2 learners do not form ergodic ensembles and that language learning data lack stability. The data…

This longitudinal study with time-serial data examines for the first time whether different types of intraindividual variation in second language (L2) performance and cognitive functioning are related, and how and when they influence L2 development longitudinally in older adulthood. We analyzed the L2 development of 26 German-speaking adults aged…

This study longitudinally examined the effects of cognitive and sociopsychological individual differences (aptitude, motivation, personality) and the quantity and quality of second language (L2) experience on L2 speech gains in naturalistic settings. We elicited L2 spontaneous speech from 50 Chinese learners of English at the beginning and the end…

Millions of public-school students in the United States are identified as English language learners (ELLs), whose academic success is tied to their second language (L2) English education. Previous research in adult populations indicates that L2 proficiency is related to the contextual variable of the prevalence of one's first language (L1) among…

Purpose: This longitudinal study investigated the trajectory of Spanish article accuracy in Spanish-English dual language learners (DLLs) from preschool to first grade, addressing the need for longitudinal data on the variability of Spanish grammatical skills in DLLs in English immersion classrooms. Method: Language sample analysis was conducted…

Spanish-speaking students constitute the largest subgroup of emergent bilingual (EB) students in the United States. Using longitudinal data on a nationally representative sample of Spanish-English EBs, we explore profiles of English reading trajectories and how early individual differences (i.e., early Spanish reading and English oral proficiency)…

In this preregistered, longitudinal study of early code-switching, 34 US-born, Spanish-English bilingual children were recorded with a bilingual family member at 2;6 and 3;6, in Spanish-designated and English-designated interactions. Children's Spanish and English expressive vocabulary and their exposure to code-switching were measured through…

This study examines the extent to which extra-linguistic factors such as language dominance, order of acquisition and language of instruction are deterministic for multilingual transfer selection and subsequent development. We test two groups of Catalan-Spanish bilinguals acquiring English as an L3 in a controlled setting. We first examine…

This study investigated whether L2 English learners' prosodic properties in speech acts change as they are immersed in the English-speaking academic community over time, and if so, what individual and contextual factors (proficiency, orientation to language study, and target language contact) potentially affect these changes. Forty-seven Japanese…

Several aspects of early language skills, including parent-report measures of vocabulary, phoneme discrimination, speech segmentation, and speed of lexical access predict later childhood language outcomes. To date, no studies have examined the long-term predictive validity of novel word learning. We examined whether individual differences in novel…

Several aspects of early language skills, including parent-report measures of vocabulary, phoneme discrimination, speech segmentation, and speed of lexical access predict later childhood language outcomes. To date, no studies have examined the long-term predictive validity of novel word learning. We examined whether individual differences in novel…

A number of longitudinal studies of L2 production have reported frequency effects wherein learners' produce more frequent words as a function of time. The current study investigated the spoken output of English L2 learners over a four-month period of time using both native and non-native English speaker frequency norms for both word types and word…

Current quantitative methods in second language (L2) acquisition have proven useful in examining how phraseological unit production changes over time. However, these methods are limited in that they do not allow for the analysis of individual differences in those changes. This study demonstrates the potential for Latent Curve Modeling, a type of…

In a longitudinal design, 51 low-achieving adolescents' development in writing proficiency from Grades 7 to 9 was measured. There were 25 native-Dutch and 26 language-minority students. In addition, the roles of (1) linguistic knowledge, (2) metacognitive knowledge, and (3) linguistic fluency in predicting both the level and development of writing…