二语悉得大师Rod Ellis在二语悉得概论中的一段关于研究悉得理论目的的话是什么呢？

我看了3个小时多，是（告诉你外语学习的真实方法及误区）里看的，我直接发给你吧，希望对你有帮助，我就从中受到很大的启发。

SLA is not a uniform and predictable phenomenon. There is no single way in which learners acquire a second language. SLA is the product of many factors pertaining to the learner on the one hand and learning situation on the other. It is important, therefore, to start by recognizing the complexity and diversity that results from the interaction of these two sets of factors. Different learners in different situations learn a second language in different ways. Nevertheless, although the variability and individuality of language learning need to be emphasized, the study of SLA assumes interest only if it is possible to identify aspects that are relatively stable and hence generalizable, if not to all learners, then, at least, to large groups of learners. The term‘second language acquisition’is used to refer to these general aspects.

SLA is not a uniform and predictable phenomenon. There is no single way in which lea