Sensitive periods, language aptitude, and ultimate L2 attainment

Research on second language acquisition (SLA) has identified language aptitude and age of onset (AO), i.e., the age at which learners are first meaningfully exposed to the L2, as robust predictors of rate of classroom language learning and level of ultimate L2 attainment in naturalistic settings, respectively. It is not surprising, therefore, that recent years have witnessed a surge of interest in...