Mechanisms underlying word learning in second language acquisition

Abstract

One common assumption in the second language acquisition literature is that learning words in a second language (L2) is somehow distinct from acquiring new words in a native language (L1), particularly for beginning adult learners. Indeed, several models of the bilingual lexicon ascribe a special status or protection mechanism (often lexical mediation via the L1 translation equivalent) to new L2 words during early stages of acquisition (e.g., Grainger, Midgley, & Holcomb, 2010; Kroll & Stewart, 1994; Kroll, Van Hell, Tokowicz, & Green, 2010). In this chapter, we examine this assumption by comparing parasitic models, which posit such separate learning processes for L1 and L2 words, and non-parasitic models, which do not. To do so, we review empirical evidence related to word learning in beginning adult L2 learners, with a focus on the influence of the lexical and conceptual knowledge from their L1. Are there factors that differentially affect word learning in the L1 versus the L2 or at different levels of L2 proficiency? If so, how can identifying these factors inform our understanding of the underlying mechanisms? Answering these questions challenges the notion that a special mechanism is necessary for L2 word learning in adults and outlines a research agenda to gain further insight into these issues.