This paper examines evidence for relationships among individual differences (IDs) in L1 achievement, L2 aptitude, and L2 achievement. It begins by providing an overview of my academic journey from L1 educator to L2 researcher and explains the development of the Linguistic Coding Differences Hypothesis (LCDH). Next, I review Peter Skehan's…

Studies with U.S. secondary second language (L2) learners have revealed individual differences (IDs) in first language (L1) skills and L2 aptitude and shown that these IDs are related to L2 achievement and proficiency. In this study, U.S. students were administered measures of L1 achievement, L1 cognitive processing, and L2 aptitude; followed…

Foreign language educators have developed measures to assess the proficiency of U.S. high school learners. Most have compared language learners to clearly defined criteria for proficiency in the language (criterion-referenced assessment) or to the performance of other monolingual English speakers (norm-referenced assessment). In this study, the…

The simple view of reading (SVR) model proposes that reading comprehension is the product of word decoding and language comprehension, and that both components make independent contributions to reading skill (Gough & Tunmer, 1986). The model posits that there are good readers and three types of poor readers--dyslexic, hyperlexic, and garden…

The Foreign Language Classroom Anxiety Scale (FLCAS) has been challenged on the grounds that it may also assess language learning skills. In this study, 128 students who had been administered measures of first language (L1) skills in elementary school were followed from 1st to 10th grade. Fifty-three students had completed second language (L2)…

In this article, I describe studies conducted over 25 years with secondary and post-secondary L2 learners in the United States. The evidence from these studies shows that there are important connections between students' early L1 skills and their L2 aptitude and L2 proficiency and that individual differences in students' L1 skills in elementary…

A factor analysis of a test battery that included early first-language (L1) achievement, L1 cognitive ability, second-language (L2) aptitude, and L2 affective measures to predict oral and written L2 proficiency was conducted. The analysis yielded 4 factors that were labeled Language Analysis, composed of L1 and L2 language comprehension, grammar,…

Fifty-four students were followed over 10 years beginning in first grade to determine best predictors of oral and written second language (L2) proficiency. Predictor variables included measures of first language (L1) skill administered in first through fifth grades, L1 academic aptitude, L2 aptitude (Modern Language Aptitude Test), and L2 affect…

Despite the lack of empirical evidence, the term "foreign language learning disability" (FLLD) has become popular in the learning disabilities (LD) and foreign language literature. I contend that there is not a unique "disability" for foreign language learning and suggest instead that foreign language skills run along a continuum of very strong to…

Fifty-four students were followed over 10 years and tested with native language measures in first through fifth grades and measures of foreign language aptitude and foreign language proficiency in high school. All students had completed two years of Spanish, French, or German. Students were divided into three groups based on their scores on the…

Colleges and universities often permit students classified as learning disabled (LD) and other students not classified as LD to substitute courses for or waive the foreign language requirement. The Modern Language Aptitude Test (MLAT) has become an increasingly popular assessment tool to determine which students can or cannot pass foreign language…

Based on the results of native and foreign language assessments of high school learners, it is inferred that students with foreign language learning difficulties have subtle but underlying native language learning difficulties, especially in the phonological and syntactic codes of language. Implications for diagnosis and teaching are discussed.…