Reexamining the robustness of aptitude in second language acquisition

Research on language aptitude has focused extensively on instructed second language (L2) learning and rate of L2 learning, but rarely on long-term L2 achievement in a naturalistic context. In addition, the few studies that have investigated the role of aptitude in morphosyntactic L2 attainment (e.g. Abrahamsson & Hyltenstam 2008; DeKeyser 2000; DeKeyser et al. 2010; Granena & Long 2013), have yielded mixed findings, in spite of having relied on the same type of outcome measure (i.e. a grammaticality judgment test; GJT). The aim of the present study was to investigate the relationship between aptitude and long-term L2 achievement as measured in two GJT modalities and sentence complexity conditions. Results showed an interaction between aptitude and GJT scores according to test modality in the L2-speaker group.