时间状语从句 when, whenever, while, as, before, after, since, till,until once（一旦）
地点状语从句 where, wherever
原因状语从句 because, since, as, for, now that（既然，由于）
目的状语从句 in order that(为了，以便), so that, that,
结果状语从句 so…that, so that, such…that
条件状语从句 if, unless, as(so)long as,
让步状语从句 though, although, even if, even though, however, whatever, as,
比较状语从句 as…as, so…as, than
1、Even thought even if 即使，尽管
2、As 当……时候 因为 同时 尽管 与…..一样 正如 依照 随着
. as单独引导定语从句
as单独引导定语从句时，先行词可以是一个词，也可以是一个句子或短语。例如：
(1) She is late, as is often the case.她迟到了，这是经常的事。(先行词是整个主句)
(2) To shut your eyes to facts, as many of you do, is foolish.对事实视而不见--你们好多人都是如此的愚蠢。(先行词是不定式短语)
3、Since
自…..以来，从….以后
因为
难点提示：用条件状语从句时要注意时态的正确使用,当主句是将来时的时候,从句要用一般现在时.
1. We will stay at home if my aunt ________ to visit us tomorrow.
A. comes B. come C. will come D. is coming
2. I’ll go swimming with you if I ________ free tomorrow.
A. will be B. shall be C. am D. was
3. In the exam, the ________ you are, the _______ mistakes you will make.
A. careful; little B. more careful; fewest C. more careful; fewer D. more careful; less
4. You should finish your lessons _______ you go out to play.
A. before B. after C. when D. while
5. I hurried _____ I wouldn’t be late for class.
A. since B. so that C. as if D. unless
6. It is ______ that we’d like to go out for a walk.
A. a lovely day B. too lovely a day C. so lovely a day D. such lovely a day
7、Mary had ______ much work to do that she stayed at her office all day.
A. such B. so C. too D. very
8、 The boy ___ to bed ___ his mother came in.
A. went not; until B. didn't go; after C. went; until D. didn't go; until
9、 May I sit nearer___I can see more clearly?
A. as if B. so that C. even if D. so
10、 ___ he came to study in the university, he has made much progress in the study of English.
A. While B. When C. Since D. After
