because, since, as,seeing that, now that, in that, considering that, given that.
The higher income tax is harmful in that it may discourage people from trying to earn more.
目的状语从句
so that, in order that，lest, in case, for fear that，in the hope that, for the purpose of , to the end that
The teacher raised his voice on purpose that the students in the back could hear more clearly.
结果状语从句
so … that, such … that, so that...，such that, to the degree that, to the extent that, to such a degree that,
To such a degree was he excited that he couldn’t sleep last night.
so +many 或few+复数可数名词 +that
条件状语从句
if, unless,whether(whether...or not)，as/so long as, only if, providing/provided that, supposing that, in case（美语中表条件，英语中表目的）, on condition that
You will certainly succeed so long as you keep on trying.
主将从现，主情从现，主祈从现
主句是将来时的时候,从句要用一般现在时.
He will not leave if it isn’t fine tomorrow.
主句为情态动词作为谓语时，从句要用一般现在时。
虚拟语气
1.与现在事实相反 主句过去将来时，从句过去时 可记为 if did , would do
2.与过去事实相反 主句过去将来完成时，从句过去完成时 if had done , would have done
3.与将来事实相反 主句过去将来时，从句过去将来时 if should do ,would do 或 if were to do ,would do 或 if did , would do 详见虚拟语气词条。
让步状语从句
though, although, even if, even though，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, whatever, whoever, wherever, whenever, however, whichever
Much as I respect him, I can’t agree to his proposal.
比较状语从句
as(同级比较), than(不同程度的比较)，the more … the more …（越来...越...） ; just as …， so…; A is to B what/as X is to Y; no … more than; not so much A as B,the 比较级 ,the 比较级.
Food is to men what oil is to machine.
方式状语从句
as, as if，the way
When in Rome, do as the Romans do.
状语从句的省略
①主句和从句的主语一致，或从句主语为it
He’ll go to the seaside for his holiday if (it is ) possible.
②从句主要动词是be的某种形式
When ( the museum is ) completed , the museum will be open to the public next year .
"简化"现象
状语从句的主语是it,且谓语动词是be时,it和be要完全简化掉
If (it is) possible, he will help you out of the difficulty.
