一、方式状语从句

　　方式状语从句通常由as(像，如同)，just as(正如)，as if/though(好像)引导。as if，as though从句若与事实相反，用虚拟语气，否则用陈述语气。

　　Do as I say!照我说的去做!

　　It looks as if it's going to rain.看起来似乎要下雨。

　　The old teacher treats students as if they were his children.这位老教师对待学生就像对待自己的孩子一样。

　　二、结果状语从句

　　1.引导结果状语从句的从属连词有：so that，so...that...，such...that...，在非正式语体中，由so...that...，such...that...引导的句子中that可以省略。

　　注意其结构形式：

　　He worked so hard that he got ill.他拼命工作，结果病倒了。

　　It was such a hard exam that few of us pass it.考试很难，结果很少有人及格。

　　注意：当so或such置于句首时， 主句要用倒装语序。

　　So fast did he walk that none of us was his equal.他走得如此快，我们没有人能比得上他。

　　2.除结果状语从句外，too...to...(太…而不能……)，enough to...(达到某种程度可以……)，so...as to...(那么……以至于……)等不定式结构同样可以表示结果。

　　He is too young to look after himself.他太小了，还不能照顾自己。

　　三、条件状语从句

　　条件状语从句通常由下列连词引导：if，unless，suppose，provided(that)，on condition that，as(so)long as，in case等。

　　Unless the rain stops，we shall not go out for play.除非雨停了，否则我们就不出去玩。

　　As long as we don't lose heart，we'll be able to catch up with others.只要我们不丧失信心，我们就能赶上别人。

　　四、比较状语从句

　　比较状语从句通常由下列连词引导：as...as，than，not so(as) ...as，the+形容词/副词比较级...the+形容词/副词比较级...等。

　　The sooner you start，the earlier you'll get to the workplace.越早出发，越早到达工厂。

　　There is much more water in the Changjiang River than in the Yellow River.长江里的水比黄河里的水多。