Adult L2-learners Lack the Maximality Presupposition, Too! * Heejeong Ko 1 , Tania Ionin 2 , and Ken Wexler 1 1 Massachusetts Institute of Technology 2 University of Southern California This paper examines errors of article use in L2-English, and argues for similarity between L1- and L2-acquisition of articles. Our experimental data show that partitivity as discourse-given set membership contributes to overuse of ‘the’ in place of ‘a’ in L2-English, as in child L1-English. We propose that adult L2-English learners have difficulty with the Maximality presupposition for ‘the’, similarly to child L1-learners (cf. Wexler 2003). The parallels between child L1- and adult L2-acquisition imply that ‘the’ overuse by learners is tied to a semantic factor rather than to children’s egocentricity. Our data also demonstrate that partitivity and specificity are independent factors at work in L2-acquisition. 1. Introduction Investigation of parallels between adult second language (L2) and child first language (L1) acquisition has been at the center of intensive research in current acquisition studies (see Flynn 1987; Thomas 1989; Neeleman & Weerman 1997; Ionin & Wexler 2002; Schwartz 2003; Unsworth 2004, among others, for child-adult comparisons). The shared assumption underlying this research program is that parallels between L2 and L1 acquisition can deepen our understanding of the general human ability to acquire language. Adult L2 data reveal the process of language acquisition uninfluenced by the concurrent cognitive growth of child L1 learners. Child L1 data reveal language acquisition patterns unaffected by L1-transfer. Parallels between adult L2 and child L1 data, thus, constitute evidence that the course of language acquisition is determined (at least partly) by universal linguistic factors which are separate from L1- transfer and cognitive growth. This paper investigates such L1-L2 parallels in the domain of English article usage, and argues for similarity between L1 and L2 acquisition of article semantics. In particular, we examine L2 acquisition of English articles by adult L1-Korean speakers. Since Korean lacks articles (or direct parallels to articles in other domains of the grammar), it is unlikely that L1-transfer plays a crucial role in L2-English article use by Korean speakers. For the purposes of this paper, we abstract away from the issue of L1-transfer and ask what factors guide L2- acquisition of English articles in the absence of articles in the L1 (see also Ionin, * We are grateful to Suzanne Flynn, Andrea Gualmini, Irene Heim, Philippe Schlenker and Carson Schütze for helpful discussion and comments. Thanks to the members of the Wexler Lab and to the participants of BUCLD 29 and GALANA 2004, where earlier versions of this paper were presented.