定义：
A 状语主要是用来修饰动词和形容词的,以表明动作发生或状态存在的时间,地点,原因,等.
1 Ten years ago, She began to live in Dalian.
时间状语修饰began
2 The boy was praised for his bravery.
原因状语修饰was praised
B 状语从句就是用一个句子来代替上面的时间状语和原因状语.
1 Ten years ago, she began to live in Dalian.
When she was 12 years old, she began to live in Dalian.
2 The boy was praised for his bravery.
The boy was praised because he saved the baby’s life in the freezing river.
二 状语从句的种类：
A 时间状语从句:
连接时间状语从句的连接词有:
(1) 连词：when, while, as. 它们都表示当…时候的意思.如果主句和从句的动作同时发生且都是进行时
态,只用while, as. 其他情况下when, while, as通用.
1 When he came in, I was listening to the radio．
2 As I was wandering in the street, I met her.
3 While (as) I was watching TV, my mum was cooking in the kitchen.
(2) 连词before, after, since, until(till). 当他们表示时间时,他们既是介词又是连词.
{ He usually drinks a cup of tea before he goes to school.
连词
He usually drinks a cup of tea before going to school.
介词
{
He usually drinks a cup of coffee after he comes back from school.
连词
He usually drinks a cup of coffee after coming back from school.
介词
{
I have lived in Dalian since my son was born in 1999.
连词
通常情况下,主句用现在完成时,从句用一般过去时.
I have lived in Dalian since 1999.
介词
{
I will wait here until(till) you finish your job.
连词
I will wait here until(till) 8pm.
介词
(3) 词组：as soon as
{ I will tell him as soon as he comes back.
As soon as she finishes her homework, she will play tennis.
通常情况下,主句用一般将来时,as soon as 引导的从句用一般现在时.
B 地点状语从句：
连接地点状语从句的连接词有：where, wherever=no matter where:
1 Where there is water, there is life.
2 Where there is a will, there is a way.
3 Wherever you go, I will follow you.== No matter where you go, I will follow you.
4 I will go wherever I can find a good job.== I will go no matter where I can find a good job.
C 原因状语从句：
连接原因状语从句的连接词有：because, as, since, for.
1 Tom was late for school this morning because he didn’t catch the early bus.
2 I couldn’t go to Beijing on business as my mother was ill.
3 Since all of us agreed about this plan, we will carry it out next week.
4 We listened carefully, for the speech was very important.
注意：
当连接原因状语从句时,because语气最强,as, since, for次之；because, as, since引导的从句可在主句前面或后面, for引导的从句只能在主句的后面.
D 条件状语从句：
连接条件状语从句的连接词有：if, unless, as long as.
1 If I am not busy tomorrow, I will play football with you.
2 You won’t pass the exam unless you work hard on it.
3 As long as you take my advice, you will outwit your rival.
注意：
一般情况下,if, unless, as long as 引导的从句用一般现在时,主句用一般将来时.
E 让步状语从句:
连接让步状语从句的连接词有：although, though, even if, even though, however, whatever, whenever, whoever, whichever.
1 Although (though) I gave him some advice, he didn’t take them.
2 John continued to work hard even if (even though) he felt sick.
3 Whatever you do, I will support you.==No matter what you do, I will support you.
4 Whoever you may be, I will not let you in. ===No matter who you may be, I will not let you
in.
5 However difficult it may be, we will overcome it. === No matter how difficult it may be, we
will overcome it.
注意：
一般情况下,although等于though, even if等于even though, however等于no matter how, wh-ever等于 no
matter wh-．
F 方式状语从句:
连接方式状语从句的连接词有：as, as if, as though.
1 You should do your homework as Tom did.
2 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.
G 目的状语从句:
连接目的状语从句的连接词有：so that, in order that.
1 Cherry was walking quickly so that (in order that) she could arrived at the cinema in time.
2 John sent the mail by air in order that (so that) it might arrive a little early.
注意：
通常情况下,so that 等于in order that.
H 结果状语从句：
连接结果状语从句的连接词有：so…that, such…that.
{ He ran so fast that we couldn’t keep up with him.
She spoke English so clearly that all of us could understand her.
{ She is such a nice teacher that all of us love her.
She is a so nice teacher that all of us love her.
{ The chef cooked such nice food that we ate up at the end of the dinner.
The chef cooked so nice food that we ate up at the end of the dinner.
{ These were such interesting books that we kept reading until the end of the class.
These were so interesting books that we kept reading until the end of the class.
注意区别：
{ such + a + 形容词+ 可数名词单数 + that 或 such + 形容词 +可数名词复数或不可数名词 + that
a + so + 形容词 +可数名词单数 + that 或 so + 形容词 +可数名词复数或不可数名词 + that