1、地点状语从句由连词where, wherever等引导，例如Make a mark where you have a question, 在你有疑问的地方做个标记
2、原因状语从句由连词because, as, since, when（既然）, now that等引导，如the little boy was crying because he was criticized
3、目的状语从句由so that, in order that, in case等引导，例如my little brother studied hard so that he could pass the exam
4、结果状语从句由so that, so ....that..., such... that....等引导，例如she was ill, so that she didn't attend the meeting， 她生病了，所以她没能参会
5、需要注意的是so是副词，只能修饰形容词或副词，而such是形容词，可修饰名词或名词词组，例如he runs so quickly that none of us can catch up with him, he is such a smart boy that we all like him
6、比较状语从句由than, as...as(和...一样）， not so ... as（不像...那样，不如），the +比较级.., the+比较级..等引导，可用句式还有A is to B what/as X is to Y
