The impact of single versus multiple recasts on L2 learners' implicit and explicit knowledge

Recasts have been the object of extensive theoretical and empirical investigation in second language acquisition research since the mid-1990s. Despite being acknowledged to have a facilitative effect on second language (L2) learning, the extent of their acquisitional contribution is a matter of controversy. This study examined the effectiveness of single and multiple recasts (SR & MR) on the acquisition of a planned target structure, as represented on the learners' implicit and explicit knowledge. The participants were three intact groups of English as a foreign language (EFL) learners at a language institute in Iran. The two experimental conditions received respective recasting on errors of English unreal conditionals. All groups – including a third control condition – were then tested via three discrete tasks aimed at measuring their implicit and explicit knowledge: an elicited oral imitation task, a timed grammaticality judgment task, and an untimed grammaticality judgment task. The results revealed that both groups exhibited improvements on both measures along immediate and delayed occasions. However, their performance over the two implicit knowledge measures yielded dissimilar outcomes. Pedagogically speaking, it must be realized that recasting would not necessarily lead to acquisition unless L2 teachers become more conscious of where and how to orchestrate them.