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…

The first part of this dissertation conducts a large-scale study comparing general and usage-based indices of syntactic complexity in L2 Mandarin writing samples across a wide range of proficiency levels. To do this, the Tool for the Automated Analysis of Syntactic Sophistication and Complexity (TAASSC; Kyle, 2016) was adapted for Mandarin by…

This quantitative study examined teachers' self-efficacy in teaching multilingual learners (MLL) and implementing the Sheltered Instruction Observation Protocol (SIOP) to support MLL instruction in classrooms. The problem is that teachers' self-efficacy when teaching MLLs may affect them not utilizing the best research-based Tier 1 instructional…

Language is a quintessentially human trait. Many decades of neurolinguistic research provided evidence of neural structures which specialize in complex linguistic and cognitive processes supporting human communications. Because the world is multilingual, (Crystal, 2010; de Bot, 2019) a prominent question related to brain processes supporting…

This dissertation developed a new learner corpus of Japanese and introduced an error and linguistic annotation scheme specifically designed for Japanese particles. The corpus contains texts written by learners who are in the first year to fourth year university level Japanese courses. The texts in the corpus were tagged with part-of-speech and…

This quantitative study evaluated how teaching models for language acquisition--the Integrated, the Stand-Alone and the Mixed Model--and student characteristics--gender and disability status--relate to growth in language skills among ELL students. In this study, the New York State English as a Second Language Achievement Test scores of the…

This dissertation investigates the initial and ongoing motivations of language revitalization practitioners. This study extends our understandings of language revitalization from the programmatic and sociological levels to the level of the individual practitioner. It also extends theory in L2 motivation into a largely unstudied language learning…

The purpose of this mixed-methods sequential explanatory study was to investigate the effects of watching text-relevant video segments on reading comprehension of a culturally unfamiliar text when technical words are present or absent. Therefore, 44 adult English Language Learners (ELLs) with higher-intermediate to advanced English language…

When acquiring a second language, learners must become able to perceive the difference between novel sounds ("discrimination") and also associate strings of sounds with distinct vocabulary items ("lexical encoding"). Recent research has questioned whether discrimination is a sufficient or necessary condition for encoding, and…

The benefit of parental involvement (PI) cannot be underestimated, most specifically, the PI that operates on mutual trust and respect, and balancing of power between homes and schools. It is particularly beneficial to students who are learning English as a second language because their parents can partner with educators to close the achievement…

Language learners need to map a continuous, multidimensional acoustic signal to discrete abstract speech categories. The complexity of this mapping poses a difficult learning problem, particularly for second language learners who struggle to acquire the speech sounds of a non-native language, and almost never reach native-like ability. A common…

This dissertation investigates how bilinguals use their two grammars to comprehend written intra-sentential codeswitches. I focus on adjective/noun constructions in Spanish and English where I manipulate the congruence of grammatical word order in the two languages across the codeswitch boundary. This allows me to test three codeswitching…

Instructional technology in courses of K-12 level for English as a Foreign Language (EFL) learners demonstrates numerous benefits for their learning, including increased engagement and improved academic outcomes. However, integrating technology into teaching practices heavily relies on teachers' competence in technology. Even though teacher…

This dissertation analyzes the production and perception of lexical stress in trilinguals' first, second, and third languages (L1, L2, and L3) to evaluate how the cue-weighting transfer hypothesis applies to L3 acquisition. According to this hypothesis, acoustic cues to stress have different weights across languages, and results from both…

The purpose of this qualitative case study was two-fold: to determine if professional learning that blends cultural competencies and second language acquisitions helped teachers in helping ELL students achieve academic success and the development of the Second Language Acquisition and Cultural Competency Practices Questionnaire. Subjects were…