四大条件状语从句

1 时间状语从句 【adverbial clause of time】：

Ø 常用引导词：When, while, as, after, before, as soon as, since, till

2 原因状语从句 【adverbial clause of cause】：

Ø 常用引导词：because, since, as, for

Ø 特殊引导词：seeing that, now that, in that, considering that

3 条件状语从句 【adverbial clause of condition】

Ø 常用引导词：if, unless,

Ø 特殊引导词：as/so long as, only if, providing/provided that, supposing that, in case that, on condition that

4 让步状语从句 【adverbial clause of concession】

Ø 常用引导词：though, although, even if, even though

Ø 特殊引导词： as（用在让步状语从句中必须要倒装），while（一般用在句首），no matter …, in spite of the fact that, while, whatever, whoever, wherever, whenever, however, whichever