§状语从句的种类（九种）
口诀：
▪ 时地原因条状补，
▪ 目比结果方让步，
▪ 连词引导各不同；
▪ 主句通常前面走，
▪ 连词引导紧随后，
▪ 从句若在主前头，
▪ 主从之间有个逗。
用来修饰谓语动词、其它动词、定语、状语或整个句子的从句叫做状语从句。状语从句可分为：
1.时间状语从句；(adverbial clau of time)
2.地点状语从句；(adverbial clau of place)
3.原因状语从句；(adverbial clau of cau)
4.条件状语从句；(adverbial clau of condition)
5.目的状语从句；(adverbial clau of purpo)
6.让步状语从句；(adverbial clau of concession)
7.比较状语从句；(adverbial clau of comparison)
8.方式状语从句；(adverbial clau of manner)
9.结果状语从句。(adverbial clau of result)
§状语从句的时态特点
一般情况下，时间和条件状语从句的谓语动词一般用“一般现在时”表示“一般将来时”，用“现在完成时”表示“将来完成时”。例如：
1.时间状语从句；(adverbial clau of time)
①由when, while, as引导的时间状语从句。例如：
When we got home, I find Tom.
While my wife was reading the newspaper, I was watching TV.
We always sing as we walk.我们总是边走边唱。
②由before和after引导的时间状语从句。
It will be four days before they come back. 他们要过四天才能回来。
After you think it over, plea let me know what you decide.你仔细考虑过以后，告诉我你是怎样决定的。
③由till或until引导的时间状语从句。till和until一般情况下两者可以互换，但是在强调句型中多用until。并且要注意的是：如果主句中的谓语动词是瞬时动词时，必须用否定形式；如果主句中的谓语动词是延续性动词时，用肯定或否定形式都可以，但表达的意思不同。
I worked until he came back.我工作到他回来为止。
I didn't work until he came back.他回来我这才开始工作。
④由since引导的时间状语从句。 since引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。一般情况下，从句谓语动词用一般过去时，而主句的谓语动词用现在完成时。但在It is ＋时间＋since从句的句型中，主句多用一般现在时。
I have been in Beijing since you left. 自从你离开以来，我一直在北京了。
⑤由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引导的时间状语从句。这些连词都表示“一……就”。
I will go there directly I have finished my breakfast. 吃完早饭，我立即到那里。
The moment I heard the news, I hastened to the spot.我一听到消息，马上赶到了出事地点。
As soon as I reach Canada, I will ring you up. 我一到加拿大，就给你来电话。
【注意】hardly(scarcely, rarely)…when / before, no sooner…than相当于as soon as之意。主句用过去完成时，从句用一般过去时。当hardly, scarcely, rarely和no sooner位于句首时，主句应用倒装语序。例如：
He had no sooner arrived home than he was asked to start on another journey. 他刚到家，就被邀请开始另一旅程。
No sooner had the sun shown itlf above the horizon than he got out of bed to commence work.太阳刚从地平线上升起，他就起床劳动去了。
⑥由by the time引导的时间状语从句。注意时态的变化：在一般情况下，如果从句的谓语动词用一般过去时，主句的谓语动词用过去完成时；如果主句的谓语动词用一般现在时，主句的谓语动词用将来完成时。
By the time you came back, I had finished this book.到你回来时，我已经写完这本书了。
⑦由each time, every time和whenever引导的时间状语从句。
Each time he came to Harbin, he would call on me. 他每次来哈尔滨，总是来看我。
2.地点状语从句；(adverbial clau of place)
地点状语从句一般由连接副词where, wherever等引导，已经形成了固定的句型。
句型1：Where＋地点从句，（there）＋主句。
Where they went, there they were warmly welcomed.他们走到哪里都受到热烈欢迎。
Where there is a will, there is a way. 有志者事竟成。
地点状语从句与定语从句的区别在于分句在句中作什么成分。作状语，则是状语从句；作定语修饰名词，则是定语从句 where引导定语从句时，从句前应有一个表示地点的名词作先行词；而状语从句前则无需先行词。 如： Go back where you came from.(where引
导地点状语从句） 你从何处来到何处去。 Go back to the village where you came from.(where引导定语从句，修饰village)
句型2：Anywhere/ wherever＋地点从句，＋主句。
【注意】anywhere本身是个副词，但是，常可以引导从句，相当于连词，意思相似于wherever, anywhere引导的从句可位于主句之前，也可以位于主句之后。 而wherever本身就是个连词，表示“在何处，无论何处”。
Wherever you go, I’ll be right here waiting for you.
Plea put the pen where you find it.
3.原因状语从句；(adverbial clau of cau)
由becau, as ,since引导
I didn’t go ，becau i was afraid。
4.条件状语从句；(adverbial clau of condition)
连接条件状语从句的连接词有：if, unless, as long as.
If I am not busy tomorrow, I will play football with you.
You won’t pass the exam unless you work hard on it.
As long as you take my advice, you will beat your rival.
5.目的状语从句；(adverbial clau of purpo)
连接目的状语从句的连接词有：so that, in order that.
Cherry was walking quickly so that (in order that) she could arrived at the cinema in time.
6.让步状语从句；(adverbial clau of concession)
连接让步状语从句的连接词有：although, though, even if, even though, however, whatever, whenever, whoever, whichever.
Although (though) I gave him some advice, he didn’t take them.
John continued to work hard even if (even though) he felt sick.
Whatever you do, I will support you.==No matter what you do, I will support you.
However difficult it may be, we will overcome it. === No matter how difficult it may be, we will overcome it.
7.比较状语从句；(adverbial clau of comparison)
As…… as
She is as tall as I（or me）．
He works as hard as his brother（does）．
than
He is taller than I expected.
8.方式状语从句；(adverbial clau of manner)
连接方式状语从句的连接词有：as, as if, as though.
You should do your homework as Tom does.
Jerry was lying on the bed as if (as though) he was very tired.
注意：通常情况下，as if等于as though.
9.结果状语从句。(adverbial clau of result)
连接结果状语从句的连接词有：so…that, such…that.
She spoke English so clearly that all of us could understand her.
