New conceptualizations of language aptitude in second language attainment Judit Kormos Lancaster University his chapter discusses the link between working memory, phonological short-term memory and language aptitude and describes how these cognitive abilities inluence second language-learning processes. I provide a critical review of the deinitions and constructs of aptitude and elaborate on how phonological short-term and working memory and components of language aptitude might inluence processes of language learning, such as noticing, encoding in long-term memory, proceduralization and automatization, and aid second language processing and production. he chapter also considers the stability of cognitive variables in the course of language learning and presents evidence that certain components of language aptitude are prone to change with intensive exposure to second/third languages. . Introduction Research in the ield of second language acquisition (SLA) has long been concerned with the question of why students show such great variation in their language-learning success. Studies in this area have concluded that individual diferences (IDs) are the most important predictors of achievement in a second language (L2) (Dörnyei 2005). herefore, it is widely acknowledged that IDs have to be taken into consideration, both in theoretical accounts of SLA and in prac- tical pedagogical decision-making. Researchers oten point to the necessity of making further advances towards uncovering how certain IDs afect and underlie important language-learning processes (Dörnyei 2005; Kormos & Sáfár 2008; Robinson 2005). he individual factors that inluence language learning have been widely researched in the past thirty years (for a recent overview see Dörnyei 2005). he variables in which language learners difer are generally subdivided into afective, cognitive and personality-related individual diferences (Gardner 1985). With some overlaps, motivation, language-learning anxiety and self-conidence are generally listed among afective factors, whereas personality-related diferences