The Effects of Instruction on L2 Acquisition

Instruction has always been a key component of the second/foreign language learning experience of most learners but its role in the acquisition of a second/foreign language (L2) has been controversial ever since antiquity. Throughout the years language teachers have often wondered about the discrepancy between what their students are taught, what they learn and (seem to) know, and what they can actually produce in their L2. But whatever their allegiance to or preference for a particular teaching method, all language teachers will probably agree that some kind of instruction will be necessary, or at least beneficial, for successful L2 learning. The research community, however, is more divided. On the one hand there are researchers who believe that L2 learning is essentially an intuitive process guided by innate mechanisms which cannot be influenced by pedagogical intervention. On the other hand there are those who believe that instruction is effective in its own right, that it can make a difference in how (well) learners learn an L2, and that in some cases (i.e. for some types of learners or for some aspects of language and language proficiency), instruction will even be necessary for successful L2 learning. Fuelled by this debate, the past two decades have seen an explosion of research on the role and the effects of instruction in L2 learning. The aim of this article is not to present a comprehensive review of this research but, rather, to propose a general framework for investigating the role and effects of instruction in L2 learning and to synthesize general research findings in terms of this framework. The first part of the article starts by defining key terms, such as learning, teaching and instruction. Then we briefly provide a background about the nature of L2 learning, L2 knowledge and proficiency, and L2 use necessary for understanding the variegated roles and effects of instruction. The second part of the article discusses the different effects which instruction may have on the L2 learning process in terms of the issues addressed in the first part. We conclude by discussing a number of factors that need to be taken into account in determining whether and how instruction effectively influences L2 learning, including an analysis of cross-linguistic influence on the level of difficulty of the target features taught.