Second versus Third Language Acquisition: Is There a Difference?

Previous research has investigated whether knowing more than one language will help adult learners acquire additional languages, with mixed results (e.g., Eisenstein, 1980; M. Thomas, 1990). It is questionable whether such enhancement, when it does exist, involves both the acquisition of lexical items and the acquisition of syntactic constructions. This study examined the latter question within a Universal Grammar (UG) parameter‐setting model of acquisition, testing matched groups of 17 Unilingual (Ul) versus 15 Multilingual (Ml) adolescent high‐school students acquiring English as a second versus third (or fourth) language, respectively. Participants were tested on their acquisition of: (a) specific verbs and their prepositional complements (lexical learning) and (b) preposition stranding (syntactic learning). The Mls outperformed the Uls in both types of acquisition, suggesting that qualities attributed to Mls, that is, heightened metalinguistic skills (J. Thomas, 1988, 1992), enhanced lexical knowledge (J. Thomas, 1988), and a less conservative learning procedure (Zobl, 1992), all help to trigger the setting of UG parameters.