We begin by reviewing data from Korean, Turkish, Italian and Spanish-speaking adults acquiring German without formal instruction. Our findings have shown that these learners transfer their L1 VPs: the Korean and Turkish speakers transfer a head-final VP and the Italian and Spanish speakers first transfer a head-initial VP and then switch its headedness to the correct, head-final value for German. Although functional projections in Korean and Turkish are head-final and in Italian and Spanish head-initial, all four groups of learners subsequently posit head-initial functional projections in German (which are not always target-like). We conclude that only lexical projections constitute the L2 learner's initial state; the development of functional projections is driven solely by the interaction of X'-Theory with the target-language input. We then discuss some studies on the acquisition of French by English speakers and of English by speakers of various L1s which purport to bring evidence to bear against our approach. Upon closer examination, the evidence turns out to offer further support for the position that the sole projections which the learner transfers from the L1 are lexical ones. Finally, we account for potentially problematic verb-raising data from French learners of English. Rather than taking the stance that French raising to Agr is transferred, we propose that L2 learners' identification of free morphemes as salient triggers leads to a misanalysis of verb raising in English. We also apply this idea to a reanalysis of the morpheme-order studies of the 1970s.
Vainikka et al. (Mon,) studied this question.