and to test Gavruseva's aspectual features account, according to which inherent aspectual properties of the verbs such as telicity and punctuality determine which verbs will be non-finite and which verbs will not (Gavruseva, 2002;2003;2004) in child L2 acquisition. Based on longitudinal data from a Turkish child second language (L2) learner of English, we present counter evidence for both hypotheses. First, it is shown that despite the fact that the early production of past tense morphology occurs exclusively with punctual predicates, data from copula be, auxiliary do and pronominal subjects do not show any evidence for defective tense. Second, contrary to what is predicted in Gavruseva's hypothesis, the rate of uninflected punctual verbs is much higher than that of uninflected non-punctual verbs in the child L2 grammar.Keywords: child L2 acquisition, L2 tense-aspect morphology, Underspecification of Aspect Hypothesis, optional/root infinitives in L2 © 2007© SAGE 10.1177 Second Language Research 23,4 (2007); pp. 383-417 Address for correspondence: Belma Haznedar, Department of Foreign Language Education, Bogaziçi University, 34342 Bebek/Istanbul, Turkey; e-mail: haznedab@boun.edu.tr
I IntroductionIt has long been noted that grammatical morphemes cause problems for learners both in first (L1) and second language (L2) acquisition (e.g. Brown, 1973;Dulay et al., 1982). In most cases, learners exhibit optionality or variability in the use of morphology relating to tense, agreement, case and/or gender as well as functional elements such as determiners, complementizers and auxiliaries. To this end, much work in L1 and L2 acquisition since the 1970s has explored the presence or absence of verbal and nominal inflection. In regard to the verbal domain, the focus has been on the development of tense-aspect morphology in monolingual and bilingual language acquisition (e.g. Antinucci and Miller, 1976; Bloom et al., 1980;Schlyter, 1990;Shirai and Andersen, 1995;Shirai, 1998; Behrens, 2001), as well as in adult L2 acquisition (e.g. Robison, 1995; BardoviHarlig and Bergström, 1996;Slabakova, 1999;2001). Following the Aspect Hypothesis, in some of these studies L1 and L2 researchers have argued that verbal inflections in early interlanguage grammars function primarily as markers of lexical aspect. That is, when inflections emerge, they are not evenly distributed across all verbs, but mark inherent aspect, not deictic tense.In child L2 acquisition, on the other hand, recent work has mainly concentrated on the acquisition of tense and agreement morphology (e.g. Lakshmanan, 1994;Gavruseva and Lardiere, 1996;Grondin and White, 1996;Prévost, 1997;Paradis et al., 1998;Haznedar, 2001;Ionin and Wexler, 2002). With the exception of some studies (e.g. Rohde, 1996;Gavruseva, 2002;2003;2004), there has been little discussion of how tense-aspect morphology develops in child L2 acquisition. Based on longitudinal data from a Turkish-speaking child L2 learner of English, the primary aim of this article is to investigate the acquisition...