-原因状语从句语法讲解.doc

A、引导原因状语从句的连词
　 原因状语从句一般由从属连词because, as, since，now that引导。
B、because, as, since和now that的区别：
1、because“因为”，表示直接的原因，语气最强。
1）why提问的句子，必须用because回答。
2）because的从句常放在主句之后。
3）because 不能与so连用。
4）because+ 从句；because of+ 名词短语
I missed the train because I got up late.
He was angry not because we were late but because we made a noise.
-Why didn’t he come yesterday?  -Because he was ill.
2、as“因为”，语气较弱，一般放在主句前，中间用逗号隔开，表示的是明显的原因。
As he was not well, I decided to go there without him.
As it was raining hard, we had to be indoors.
3、since/ now that“既然”，一般放在主句前，中间用逗号隔开，表示的是明显的原因或众所周知的事实。
Since/ Now that this method doesn’t work, let]s try another.
Since/ Now that you feel ill, you'd better not go to work.
C、for 引导的并列句与原因状语从句的辨析
并列连词for“因为”，引导的不是从句，而是并列分句，只能放在主句之后，不能放在句首，常用逗号把它和前面的分句隔开。对主句补充说明理由或推断原因。
　　It rained last night, for the ground is wet.   
    She must have gone out early, for she had not come for breakfast.

Exercise:
一、填入恰当的连词
1. I didn’t go to school yesterday _________ I was ill.
2. ________ everybody is here, let’s begin our meeting.
3. ________ you are in poor health, you should not stay up late.
4. I asked her to stay to tea, ________ I had something to tell her.
5. ________ all the passengers are here, why don’t we start at once?
6. Bill won’t make any progress ________ he doesn’t study harder than before.
7. He might have gone to bed, ________ the light went out. 　　
二、 改写句子,保持句意不变
1) The ship changed its course because there was a storm.
The ship changed its course _______ _______ _______ _______.
2) Because he was ill, he didn’t go to school.
  He was ill, _______ he didn’t go to school.
3) He couldn't walk because his leg was broken.
He couldn't walk ______ ______ his ______ leg.
4) I came back because it was raining heavily.
  I came back ______ ______ the ______ rain.

三、课堂小结：
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________

四、回家作业：
一、填入恰当的连词
1. ______ you do not understand, I will explain again.
2. ______ Jane was the oldest in this family, she had to look after the others.
3. He must be ill, ______ he is absent today.
4. The teacher must be strict with you ______they want you to make great progress.
5. _____your father is well again, you no longer have anything to worry about.
6. The day breaks, _____the birds are singing.
7. ______ you are ill, you’d better go to see the doctor.
8. ______ she was late for class, she had to say sorry.
二、 选择恰当的答案
1. The man can’t get on the bus ______ there is no room on it.
  A. though   B. because    C. until    D so that
2. ______ her daughter hadn’t come back, ______ she looked worried.
  A. Because, /  B. Because, so   C. Though, but    D. Though, /
3._______ you’ve got a chance, you might make full use of it.
  A. Now that    B. After   C. Although    D. As soon as
4. He found it difficult to read, _______ his eyesight was beginning to fail.
  A. and    B. for    C. but    D. or
5. A man cannot smile like a child, ________ a child smiles with his eyes, while a man smiles with his lips alone.
  A. so    B. but    C. and    D. for

五、学生反馈：（在完成回家作业的过程中存在的问题）
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________

六、教师反馈：（在批改学生回家作业中发现的问题）
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________

Keys：
A、引导原因状语从句的连词：because, as, since，now that
B、because, as, since和now that的区别：
1、because：“因为”，表示直接的原因，语气最强。
1）why提问的句子，必须用because回答。
2）because的从句常放在主句之后。
3）because 不能与so连用。
4）because+ 从句；because of+ 名词短语
2、as：“因为”，语气较弱，一般放在主句前，中间用逗号隔开，表示的是明显的原因。
3、since/now that：“既然”，一般放在主句前，中间用逗号隔开，表示的是明显的原因或众所周知的事实。
C、for 引导的并列句与原因状语从句的辨析：并列连词for“因为”，引导的不是从句，而是并列分句，只能放在主句之后，不能放在句首，常用逗号把它和前面的分句隔开。对主句补充说明理由或推断原因。
课堂练习：一、1.because  2.Since  3.As  4.because  5.Since  6.because  7.for
二、1.because of the storm  2. so  3. because of broken  4. because of heavy
回家作业：一、1.since  2. As  3. for  4. because  5. Since  6. for  7. Since  8. As
二、1.B  2.A  3.A  4.B  5.D