| This dissertation consists of three articles examining, both theoretically and empirically, the ultimate attainment of post-pubescent second language learners. The first article is a comprehensive review of the literature on the ultimate attainment in adult second language (L2) acquisition. Growing research evidence shows that there are some adult learners who achieve native-like proficiency in their L2 and emphasizes the necessity to study these learners in greater detail than has traditionally been done. Based on the research reviewed, several areas of study are identified that still need to be addressed by empirical research. Therefore, the second article discusses an empirical study that examined the linguistic performance of highly proficient adult L2 learners across major domains of language knowledge (e.g., pronunciation, vocabulary size, grammar and language use) and compared their performance to that of a control group of native speakers of English. Results from a multivariate analysis of variance indicate that on measures of pronunciation, vocabulary size and grammar knowledge, the group of L2 learners performed significantly worse than the group of native speakers. However, analyses of the individual performance of the L2 learners on the different tasks revealed that at least 40% of them performed within the native range. In addition, three profiles of the highly proficient learners are discussed in greater detail revealing that some of them achieve native-like proficiency across all the domains of L2 knowledge under examination. The final article isolates some background factors (e.g., age of arrival and length of residence in the L2 setting, amount of formal L2 study, intensity of L2 input, level of formal education and degree of motivation to achieve high levels of proficiency in the L2) that are associated with the L2 learners' proficiency in the different L2 domains. This analysis concluded that current experiential factors, such as use of English and its importance to the learner, best predicted the ultimate attainment in this group of highly proficient adult L2 learners. |
