Over the past decade, the LLAMA language aptitude test battery has come to play an increasingly important role as an instrument in research on individual differences in language development. However, a potentially serious problem that has been pointed out by several scholars is that the LLAMA has not yet been carefully validated. We addressed this…

Some listeners exhibit higher sensitivity to subphonemic acoustic differences (i.e., higher speech gradiency). Here, we asked whether higher gradiency in a listener's first language (L1) facilitates foreign language learning and explored the possible sources of individual differences in L1 gradiency. To address these questions, we tested 164…

Syntactic abilities vary across individuals. Weak syntax is typically ascribed to limited competence (knowledge) or poor performance (processing). However, with many questioning this dichotomy, alternative explanations should be considered. Arguments related to language exposure are insufficient because language-impaired children often have good…

Recent research has called for the use of fine-grained measures that distinguish implicit knowledge from automatized explicit knowledge. In the current study, such measures were used to determine how the two systems interact in a naturalistic second language (L2) acquisition context. One hundred advanced L2 speakers of Japanese living in Japan…

This study examined interactions of word and learner characteristics during foreign vocabulary learning, focusing on translation ambiguity and individual differences in cognitive resources and linguistic background (language proficiency, multilingual experience). Fifty-three native Hebrew speakers and Russian-Hebrew multilinguals learned the…

This study compares the performance of native speakers and adult second language (L2) learners on tasks tapping proficiency in grammar, vocabulary, and collocations. In addition, data were collected on several predictors of individual differences in linguistic attainment, including some related to language experience (print exposure, education,…

Many learners of a foreign language (L2) struggle to correctly pronounce newly learned speech sounds, yet many others achieve this with apparent ease. Here we explored how a training study of learning complex consonant clusters at the very onset of L2 acquisition can inform us about L2 learning in general and individual differences in particular.…

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, we report the results of a study on the relationship between individual differences in language learning aptitude and the structural connectivity of language pathways in the adult brain, the first of its kind. We measured four components of language aptitude ("vocabulary learning"; "sound recognition"; "sound-symbol…

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…