1. 并列连词

1) 表示意义的引申: and, both…and, not only…but(also), as well as, and …as well, neither…nor

2) 表示选择: or, either…or

3) 表示转折: but, while, whereas, yet, however/nevertheless(也可认为是副词)

4) 表示因果: for, so, therefore, hence

2. 从属连词

1) 表示时间: when, while, as, after, before, since, until(till), as soon as, once

2) 表示原因: because, as, since, now that, seeing that

3) 表示条件: if, unless, in case, provided(that), suppose, as long as, on condition (that),

4) 表示其他关系: (al)though, than, as/so…as, lest, in order that, so…that

来源:可可英语 http://www.kekenet.com/cet4/200904/67472.shtml