名词从句讲练
【概念】在句中起名词作用的从句叫名词从句。它和名词一样，在复合句中可充当_______，_______，_______和_______。根据它在句中不同的语法功能，名词从句又可分别称为主语从句，表语从句，宾语从句和同位语从句。

【名词从句的引导词通常有：】

 
I. 【主语从句】
主语从句在复合句中作________，主语从句可以位于________，但常见的主语从句多放在句末，句首则用__________________。
 例如：1. _______ the earth is round is true.
2.____________ he will come hasn’t been decided.
注意：连词that（无意义）, whether（是否）在从句中不担任句子成分，只起连接作用，不能省略。并且whether引导主语从句时不能用if代替。 
________ let out the news remained unknown.
________ side will win is not clear.
__________ bike it is hasn’t been found out.
__________ we need is more time.
__________ comes is welcome.                 
It is not clear ________ we will start.
________ he didn’t come here is not clear to anyone. 
__________ I have done is only for you.
注意：who, which, how, when, where, why在所引导的从句中可担任主语，宾语，定语，状语，且不能省略。由它们引导的从句必须是陈述句。

※另外，有的“It …＋主语从句”已成为固定结构。如：
a. It is +名词＋从句    It is a pity that we can’t go.
b. It is ＋形容词＋从句    It is clear that Tom has returned.
c. It is ＋过去分词＋从句    It is said / reported / believed / known …
d. It +不及物动词+that从句 It seems /appears/happens……
填空：
_________ he will leave for America is not decided.
___________ wants this book may take it.
It is not clear to me ________ he likes the job.
___________ he has been is still a question.
__________ he failed the physics exam wasn’t clear.
___________ was said here must be kept secret.

II. 【表语从句】
在复合句中用作表语的从句是表语从句。
That’s ________ we should do.    
That’s _________ I want to see you.  
The question is ________we should ask them for help.
The reason for my absence was ________ I was ill.
It seems __________ it is going to rain.

注意：在表语从句中，当reason作主语时，引导词只能用that，不能用because，
如：他迟到的原因是因为他没有赶上早班车。  
  The reason why he was late was ______ he didn’t catch the early bus.
练习：
The fact is ________ they never came to see me.
The question is _________ they will be able to help us.
That is ________ she did this morning in the office.
What she wants to know is ______ dress she should buy.
That is _______ Lu Xun used to live.
That is ________ the machine is started.
My suggestion is _________ we should go shopping.
China is no longer_________ it used to be.
That’s ________ he refused my invitation.

III. 【宾语从句】
在复合句中用作宾语的从句是宾语从句

1. 作动词宾语
I don’t know _______ I was thinking of.   
I expect ______I shall be back on Sunday.
在口语中，that引导宾语从句时常常省略。 如：
We don’t know (that) he has gone abroad.
若有补语，则宾语从句要放到补语之后，在宾补前用形式宾语it.
He doesn’t want it to be known ____ he is going away.    
I consider it necessary_____ he should do it again.
在think, believe, suppose等动词之后，宾语从句中谓语的否定常转移到主句的谓语上。如：
I don’t think he will see you.       I don’t believe he will go.
注：此种用法主句的主语必须是第一人称I或we. 而且它的反意疑问句的助动词由从句的助动词来定。
I don’t think he can do it, ______________?   
We don’t think you are right, ______________?
在suggest, insist, demand, order, require 等表示建议，命令，要求的动词后，从句的谓语动词要用虚拟语气。如：
I insisted that he______________(do)  it at once.    
She suggested that the work _______________(finish) at once.

2. 作介词宾语。    The teacher is satisfied with what I said.

3. 作afraid, glad, certain, sure等形容词的宾语。   
I’m afraid that I will be late.    
I’m glad that you passed the exam.

练习：
It depends on _______ you do and ______ you do it.
I don’t know _______ you were talking to.
You can take ________ you like .
We wrote a letter of thanks to ______ had helped us.
IV. 【同位语从句】
如果担任同位语的是个句子，则这个句子是同位语从句。同位语从句表示先行名词的具体内容，能跟同位语从句的名词常见的有news, idea, belief, doubt, fact, rumour, question, order, hope, thought, reply, problem, reason等。
引导同位语从句常用连词that，它在句中不担任句子成分，没有词意。除that外，还有whether, when, where, who, what, which, why, how等。可以引导同位语从句。   
They have no hope __________ he will recover.    
I have no idea _________ they have gone.
同位语从句与先行名词有时也可以分开。   
Suddenly the thought came to me _________ he could go blind.
注：同位语从句与定语从句的区别：
（1）同位语从句的先行名词极为有限，而定语从句的先行词则不计其数。
（2）引导同位语从句的连词that在句中不担任句子成分，而引导定语从句的that则在从句中作主语，宾语等。引导同位语从句的wh一词多具有疑问意义，而引导定语从句的wh一词则没有疑问意义。
（3）同位语从句与先行名词是等同关系，一个具体，一个抽象，两者常可以转述为主表关系，而定语从句与先行词是修饰与被修饰关系。比较：
The news that our team won the game is true. （________）   
 The news that you have heard isn’t true. （_______）
练习：
The fact _______ our team won the match is very exciting.
I got the news _________ she would be late.
There is doubt _________ he will come.

注：【Whether与if在名词从句中的用法】
Whether可以用于所有的名词从句中，if只用于宾语从句中，两者都不能省略。
1. 在引导宾语从句（动词宾语从句）时，whether和if可以互换，但如果出现or not则只能用whether.
I don’t know whether / if I can come. = I don’t know whether I can come or not.
2. 介词的宾语从句只能用whether引导。   
We worried about whether he was in good health or not.
3. 引导主语从句，表语从句，同位语从句时都用whether. 
The question is whether you can do it yourself.  （__________） 
Whether they will win is all the same to me.       （__________） 
The question whether he should come himself or send another one hasn’t been decided. （_______）
 4. 和动词不定式连用只能用whether.  I haven’t decided whether to go there or not.
【练习】
1. ____ She is a rich woman is known to all in the city.
A. /    B. That     C. Who     D. Because
2. My cousin asked me  ____ I could lend him the Chinese novel.
A. whether          B. /               C. that                 D. which
3. The fact ____ he was successful proves his ability.
A. that     B. what     C. which     D. why
4. ____ is a fact that English is being accepted as an international language.
A. There     B. This       C. That        D. It
5. The reason he has been such a success   ____ he never gives up.
A. is because      B. is what         C. is that             D. is
6. ____ Mathematics is the base of all other sciences.
A. This is because  B. This is that     C. It is that           D. Because
7. China is becoming stronger and stronger.  It is no longer ____.
A. what it used to be                  B. what it was used to being
C. what it used to being              D. what it was used to be
8. The reason why he hasn’t come is ____.
A. because his mother is ill          B. because of his mother’s being ill
C. that his mother is ill              D. for his mother is ill
9. The man asked ____.
A. what was going on there        B. what it was going on there
C. what’s going on there            D. what going on there
10. ____ leaves the room last ought to turn off the light.
A. Anyone      B. The person      C. Whoever     D. Who
11. It’s uncertain ____ the experiment is worth doing.
A. if     B. that     C. whether    D. how
12. ____ I have will be yours sooner or later.
A. No matter what B. No matter whatever     C. Whatever  D. That
13.I’ll eat ____ you give me.
A. no matter what     B. no matter whatever      C. whatever      D. what
14. ____ I can’t understand is ____ he wants to change his mind.
A. That; that         B. Which; what       C. What; what      D. What; why
15. I wonder how much  ____.
A. cost these shoes                  B. do these shoes cost
C. these shoes cost                  D. are these shoes cost
16. We could see the tower clearly from ____ we were standing. 
A. where         B. there          C. which        D. it
17.  ____ there is life on another planet is almost impossible.
A. How           B. That           C. Why         D. Whether
18.The demand ____ the workers ask for higher wages seemed reasonable.
A. what           B. that           C. which        D. when
19.  ____ was a well-known fact.
A. That their team was weak        B. That their team being weak
C. Their team was weak          D. If their team was weak
20. Has it been announced  ____ the planes are to take off?
A. when          B. what          C. where       D. who
21. Nobody knew ____.
A. where he comes          B. where he was from
C. where he is from         D. where does he come from
22. Father asked ____.
A. what was wrong with me        B. what’s wrong with me
C. what wrong was with me       D. what wrong is with me
23. The trouble is ____ we are short of tools.
A. what       B. that         C. how       D. why that
24. It is possible ____ he misunderstood ____ I said.
A. that;  that    B. what;   what      C. what;   that        D. that;   what
25.The fact ____ he is an orphan is well known. 
A. what         B. that       C. which       D. whether
26.  ____ in the newspaper that the Japanese Minister will arrive next Monday.
A. It says       B.  It is said       C. It has said        D. He is said
27. Comrade Wang is to give us a talk on ____ he saw and heard in Britain.
A. what          B. all what        C. that             D. which
28.That is ____ we were absent(缺席) last time.   
A. that     B.  when     C.  why     D. what
29.  ____ is announced,  all the schools will reopen soon.
A. It            B. That            C. As            D. When
30.  ____ is announced that all the schools will reopen soon.
A. It            B. That            C. Which        D. As
31.They couldn’t understand  ____ I refused.      
A. what      B. why          C. that        D. where
32.  ____ I am anxious to know is ____ we can visit the Museum.
A.What;  that   B. What;   when   C. That;  where   D. Where;   when
33. It is doubtful ____ he knows it or not.    
  A. whether        B. what     C. when         D. that
34. ---I rang you at about ten, but there was no reply.  
---Oh, that was probably ____ I was seeing the doctor.
A. when      B. why                 C. what                 D. that