Second language acquisition and first language loss in adult early bilinguals: exploring some differences and similarities

This study compares the linguistic knowledge of adult second language (L2) learners, who learned the L2 after puberty, with the potentially 'eroded' first language (L1) grammars of adult early bilinguals who were exposed to the target language since birth and learned the other language simultaneously, or early in childhood (before age 5). 1 make two main claims: (1) that the L I grammar of bilinguals at a given stabilized state (probably endstate) resembles the incomplete (either developing or stabilized) grammars typical of intermediate and advanced stages in L2 acquisition; and (2) that despite similar patterns of performance, when language proficiency is factored in, early bilinguals are better than the L2 learners, probably due to exposure to primary linguistic input early in childhood. I offer empirical evidence from an experimental study testing knowledge of the syntax and semantics of unaccusativity in Spanish, conducted with English-speaking L2 learners and English-dominant Spanish heritage speakers living in the USA. I consider recent treatments of unaccusativity and language attrition within the generative framework (Sorace, 1999; 2000a; 2000b), that offer a unifying account of the formal parallels observed between these two populations I discuss how input, use and age may explain differences and similarities in the linguistic attainment of the two groups.