While language aptitude and motivation are considered to be important contributors to second language (L2) attainment, two major gaps in the past research have been (1) a lack of nonlinear models stemming from a naive and tacit assumption that learning outcomes are linearly related to their predictors, and (2) a lack of unified and integrative…

Second language (L2) writing has been determined to be influenced by what is read, with language learners tending to borrow words and short phrases from input texts while writing (e.g., Wang & Wang, 2015). This phenomenon is referred to as lexical alignment. Only one empirical study has investigated the influence that the linguistic complexity…

As part of the Dynamic Model of Multilingualism (DMM), Herdina & Jessner (2002) cite multilinguals' increased metalinguistic awareness as one of the key factors that distinguish third language acquisition from second language acquisition. Many TLA studies have sought to show that this increased metalinguistic awareness and the beneficial…

Despite the educational advancements as the world becomes more integrated, the problem of disparity in assessment of academic value still lingers with the criteria for validating foreign students' credentials. This can leave these students unable to further their education at different universities or even different departments within the same…

Very high-level, functional ability in foreign languages is increasingly important in many walks of life. It is also very rare, and likely requires an early start and/or a special aptitude. This study investigated the extent to which aptitude for explicit learning, defined as "analytic ability" and aptitude for implicit learning, defined…

Historically, educators have had significant difficulty assessing the needs of culturally and linguistically diverse (CLD) learners, especially when determining special education classification. Hispanic students seem especially vulnerable to schools' traditionally inadequate means of assessing language ability in CLD students. Dynamic assessment…

The purpose of this dissertation was to examine the relationships between working memory (WM) and three commonly used learning strategies or conditions in the nature of proficiency among adult L2 Russian learners. Based on the aptitude-learning condition interaction framework articulated by Robinson (2002b), the study identifies two types of…

This inquiry analyzed the relationships between individual differences and gains made in oral proficiency of adult, second language learners of Spanish during one semester studying abroad. Oral proficiency was measured using a pre/post-SA Computerized Oral Proficiency Instrument (COPI, CAL, 2009). Gain scores were correlated with two cognitive…

Due to their unique profile as childhood bilinguals whose first language (L1) became weaker than their second language (L2), heritage speakers can shed light on three key issues in bilingualism--timing, input, and cross-linguistic interaction. The heritage speakers of focus in this dissertation are Korean second generation immigrants mainly…

This study examined the second language (L2) development of adult learners of Spanish at three levels of proficiency during and after a semester of instruction. A fundamental goal was to identify cognitive and psychosocial individual differences (IDs) that can explain between-learner variation over time in order to expand our understanding of the…

Bilingualism (Sanz, 2000), motivation (Pintrich, 1989), and language aptitude (Grigorenko, Sternberg, and Ehrman, 2000) are crucial individual differences that contribute to successful adult language learning. Since Gardner's (1985) seminal work on motivation, many studies have shown that motivation is dynamic and that it affects language…