As SLA research continues its exploration of how learners build up their interlanguage and how various learning activities have different effects on that process, so we piece together an ever more detailed picture of the process of second language acquisition. A number of general conclusions emerge:

• One strong insight from the study of SLA is that building up language knowledge is not simply a matter of accumulating and automatizing discrete 'bits of language', as though they were facts: language knowledge constitutes an internal system that seems to grow organically. It also needs to be practised in communicative activity, and possibly also in controlled activity, in order to ensure proceduralization and automatization.
  
  
• Further, there are probably different pathways through learning a second language, some of which work for some learners in some contexts, some of which work for others in other contexts - we have to be careful about assuming 'one size fits all'. Some learners will be good at picking language up implicitly: others may need to feel they understand grammatical concepts more explicitly.
  
  
• There is thus probably no best teaching 'method' corresponding to a single, universal process of second language learning - some hypotheses have been put forward as to which kinds of language learning activities should work best, but we still need to observe what our learners are doing and feeling, and try to understand what makes sense for them.
  
  
• Learners do not simply learn what teachers teach: they process the information they perceive, and notice aspects of it depending on their existing knowledge and orientation. We need to be aware that what seems obvious and easy to us as 'experts' may not be obvious or easy to our 'novice' learners.

It can be frustrating for the hard-pressed teacher to feel that there are, as yet, no methods or techniques that are unambiguously supported by SLA research. But this just reinforces the importance of the teacher in the classroom: only the teacher can pick up and respond to the differences between learners in a class, and the differences between the class on one day and on another day. What this module has tried to do is to alert you to the general background to your day-to-day, minute-by-minute decision-making in the classroom. What SLA can never do is tell any teacher exactly what to do. It can however try to encourage teachers to explore more closely the fascinating world of learning.