© Florence Myles
The purpose of this general overview article is to outline how research into second language acquisition (SLA) over the last few decades has fed into our understanding of learning and teaching in foreign language classrooms. After a very brief overview of SLA research findings concerning both route and rate of L2 development, theoretical models attempting to explain these findings are presented, ranging from purely linguistic to cognitive models and social/interactionist models. The relationship between SLA research and second language pedagogy is then explored. Finally, recent developments investigating specifically the relationship between instruction and L2 development are outlined. 1. Introduction
The two main, well documented findings of SLA research of the past few decades are as follows: 1. second language acquisition is highly systematic
2. second language acquisition is highly variable
Although these two statements might appear contradictory at first sight, they are not. The first one primarily refers to what has been called the route of development (the nature of the stages all learners go through when acquiring the second language - L2). This route remains largely independent of both the learner's mother tongue (L1) and the context of learning (e.g. whether instructed in a classroom or acquired naturally by exposure). The second statement usually refers to either the rate of the learning process (the speed at which learners are learning the L2), or theoutcome of the learning process (how proficient learners become), or both. We all know that both speed of learning and range of outcomes are highly variable from learner to learner: some do much better much more quickly than others. Before we expand on these findings a little more, it is important to note that, traditionally, the concern for rate of learning has been the centre of teachers' and learners' attention. This is because it has obvious pedagogical implications: if we understand what makes learners learn faster and progress further, then maybe we can be better teachers or learners. However, these two lines of enquiry are both part and parcel of the same endeavour, which is to understand thoroughly how learners learn. In fact, understanding the route learners follow, and therefore having clear expectations of what learners can achieve at given points on the developmental continuum, is crucially important for both learners and teachers. Such study leads us, for example, to a better understanding of the significance of errors in the learning process. Producing them need not be seen as necessarily problematic (in fact, some errors can be evidence of a more advanced linguistic system than the equivalent correct form: for example, learners will usually produce rote-learned formulaic questions such as 'where's X?', e.g. 'where's the ball?', in which 'where's' is an unanalysed chunk, before producing the developmentally more advanced 'where the ball is?', the second stage in the development of the interrogative system before the final stage in which 'where is the ball?' is produced correctly; See e.g. Myles et al1998 and 1999 for a discussion. This is often referred to as the 'U shape of learning', typical also of L1 learners, by which learners start with the correct rote-learned form, e.g. took, before over-applying the past tense rule and producing taked, prior to learning the exception to the rule and producing took again, creatively rather than rote-learned this time. Teachers will also be less frustrated, and their learners too, when they become aware that teaching will not cause skilful control of a linguistic structure if it is offered before a learner is developmentally ready to acquire it. Now, of course, if we can speed up progression along the route that research has identified we need to understand...