状语从句（Adverbial Clause）

状语从句就是由一个句子来充当状语。

Tom went into the classroom this morning.

When Tom went into the classroom this morning, I was teaching the kids.

1、时间状语从句-Adverbial clause of time

2、地点状语从句-Adverbial clause of place

3、原因状语从句-Adverbial clause of cause

4、目的状语从句-Adverbial clause of purpose

5、结果状语从句-Adverbial clause of result

6、条件状语从句-Adverbial clause of condition

7、让步状语从句-Adverbial clause of concession

8、比较状语从句-Adverbial clause of comparison

9、方式状语从句-Adverbial clause of manner

时间状语从句的连词（引导词）

1、常用引导词：when, as, while, as soon as, before, after, since, not...until，untill/till等。

a, when引导时间状语从句时表示当……的时候， when既可以指时间段也可指时间点，从句中既可用延续性动词又可用非延续性动词，且动作既可和主句的动作同时发生，又可以在主句的动作之前或之后发生， 如：

I'll call you when I get there.

My wife was cooking dinner when I came home.

When the wind blows, all the doors rattle.

He stopped trying, when he would have succeeded next time.

注意1：如果when引导的时间状语从句的主语与主句主语相同， 而从句的谓语又是be动词时， 那么从句中的主语和be可以省略。如：

When you are in trouble, ask her for help.

When in trouble, ask her for help.

注意2：当when引导的时间状语从句的主语与主句主语相同时， 往往还可以用“when＋分词”的形式替代该状语从句。如：

When I came into the room, I found him lying there asleep.

When coming into the room, I found him lying there asleep.

b, while引导时间状语从句时，表示当……的时候， 它强调主句的动作与从句的动作同时持续地进行，(往往侧重主句和从句动作的对比)， 用这一用法时while引导的时间状语从句和主句中的谓语动词必须是延续性动词。如：

We must strike while the iron is hot.

While my wife was reading the newspaper, I was watching TV.

c, as引导时间状语从句时表示“当……时， 一边……一边……”， 侧重表示两个动作同时发生(包括一个主语同时进行两个动作)， 或者一种动作随着另一种动作的变化而变化。As引导的动作是延续性动作。如：

I slipped on the ice as I ran home.

He played his mobile phone as he went along.

注意3：当when, as, while表示“在某段时间里”，主从句的动作同时发生时可以互换。如：

When we were discussing, Mr. Simon came in.

While we were discussing, Mr. Simon came in.

As we were discussing, Mr. Simon came in.

d, as soon as引导的时间状语从句，表示“一...就...”。如：

I will tell her the good news as soon as she comes back.

My family always go somewhere interesting as soon as winter holiday comes.

e, before引导时间状语从句时表示主句的动作发生在从句动作之前 。如：

See me before you leave.

Before you drive, you will have to pass the driving test.

f, after引导时间状语从句时表示主句的动作发生在从句动作之后。如：

I saw them after I arrived.

I found his pen after he left.

g, till和until：表示直到，一般情况下可以互换。till不能用在句首，而until可以放在句首。如：

I didn't go to bed until (till) my father came back.

I worked until (till) he came back.

Until he came back I stopped my work.

Please wait until I arrived.

h, since引导的时间状语从句，表示自从……以来，其用法主要有两种：

(1), 现在完成时的主句＋since引导的一般过去时态的时间状语从句。如：

He hasn't been home since he graduated.

They have been friends since they were in primary school.

What have you been doing since I saw you last time?

(2), It be＋表示一段时间的词汇+since引导的时间状语从句。如：

It is two years since I became a postgraduate student.

It was three years since we had been there.

It is two hours since he left the classroom.

注意4：在时间状语从句中，不能用任何一种将来时，如：一般将来时、过去将来时态或将来完成时，而要用相应的一般现在时态、一般过去时或现在完成时来代替。如:

I'll telephone you as soon as I get there.

She said she would phone me as soon as she got there.

Don't get off the bus until it has stopped.

2、特殊引导词：the moment(the day,the minute, the second), every time(each time, whenever), directly/immediately等。

The moment I heard the news, I rushed to the spot.

Every time I listen to your advice, I get into trouble.

Each time he came to Harbin, he would visit me.

Whenever that man says“To tell the truth”, I suspect that he's about to tell a lie.

I will go there directly I have finished my breakfast.

注意5：由by the time引导的时间状语从句，要注意时态的变化：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；如果从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。如：

By the time you came back, I had finished this book.

By the time you come here tomorrow, I will have finished this work.

注意6：由as long as引导的时间状语从句，表示只要。如：

You can go where you like as long as you get back before dark.