主语从句讲解与练习

主语从句讲解与练习
主语从句
一、概述：在句子中起名词作用的各种从句统称为名词性从句。

根据它们在句中的语法作用，这类从句又可分为主语从句、同位语从句、表语从句和宾语从句。

二.主语从句主要有三类：
（1）由连词that引导的主语从句:引导词that无含义,在句中不做成分,不可以省。

例如：That you will win the medal seems unlikely.
你想获得奖牌看起来是不可能的。

That you are so indifferent bothers me.
你如此冷淡使我很烦恼。

That she survived the accident is a miracle.
她在事故中幸免于难简直是奇迹。

（2）用连词whether 引导的主语从句:whether有含义(是否),在句中不做成分,不可以省。

例如：Whether she is coming or not doesn’t matter too much.
她来不来都无关紧要。

（3）用连接代词引导的主语从句(在由连接代词who, whose, whom, which, what, whoever, whomever, whichever, whatever引导的名词性从句中，其连接代词在句中起名词性作用，担当一定成分).
例如：What you need is more practice.
你所需要的是更多的训练。

What I want to know is this. 我想知道的就是这事。

Whatever we do is to serve the people.
我们无论做什么都是为人民服务。

（4）用连接副词when, where, why, how引导的名词性从句(其连接副词有含义,在句中作状语。

)
eg:Where we should leave it is a problem.
When they will come hasn’t been made pubic.
他们什么时候来还不知道。

三.注意点:
1.it 做形式主语,而将主语从句放在句末（尤其是当谓语较短时）。

例如：That light travels in straight lines is known to all.
光沿直线传播，这是众所周知的事。

=It is known to all that light travels in straight lines.
众所周知光沿直线传播。

When the plane is to take off has not been announced .
飞机何时起飞还没有宣布。

= It has not been announced when the plane is to take off.
还没有宣布飞机何时起飞。

(当what引导的主语从句表示“…的东西”时，一般不用it作形式主语。

)
错:It is a book what he wants.
对:What he wants is a book. 他想要的是本书。

例如：Has it been settled who will be sent to carry out the task ?
谁将被派去执行这项任务决定了吗？
固定用法和译法
（1）It is +名词+从句
It is a fact that… 事实是……
It is good news that … ……是好消息
It is a q uestion that … ……是个问题
It is common knowledge that … ……是常识
类似的名词还有：a pity；a wonder；a good thing；no wonder；surprise等。

例如：It is a mystery to me how it all happened.
这一切是怎么发生的是个谜。

It is common knowledge that the whale is not a fish.
鲸鱼不是鱼，这是常识。

It is no surprise that Bob should have won the game.
鲍勃会赢得这场比赛，这不足为奇。

（2）It is +形容词+从句
It is n ecessary that … 有必要……
It is clear that … 很清楚……
It is likely that … 很可能……
It is important that … 重要的是……
类似的形容词还有：strange; natural; obvious; true; good; wonderful; possible; unlikely; quite; unusual; certain; evident; worth-while; surprising; interesting; astonishing, etc.
例如：It is obvious that conductors and insulators are both important in industry.
很明显导体和绝缘体在工业中都很重要。

It is doubtful whether she will be able to come.
她是否能来令人怀疑。

It was really astonishing that he refused to talk to you .
他拒绝和你说话真是令人惊讶。

It is essential that he should be here by the weekend .
周末之前，他应该到这里是必要的。

It seems obvious that we can not go on like this.
很明显我们不能这样下去了。

（3）It is +过去分词+从句
It is said that … 据说……
It is reported that … 据报道……
It has been proved that … 已证明……
It must be proved that… 必须指出……
类似的过去分词还有：known; estimated; expected; believed; thought; hoped; noted; discussed; required; decided; suggested; demanded; made clear; found out,etc.
例如：It is thought that he is the best player.
大家都认为他是最好的选手。

It is estimated that the vase is 2000 years old.
据估计这个花瓶有2000年的历史。

It is used to be thought that a new star must be due to a collision between two stars. 过去一直认为新星是由于两颗星星之间碰撞产生的。

It has not been made clear when the new road is to be opened to traffic.
还没弄清楚这条路将开始通车。

It does not matter if I missed my train, because there is another later.
没有赶上这趟火车没有关系，稍晚还有一趟。

It happened that I saw him yesterday.
碰巧我昨天看见他了。

当“及物动词+ 宾语”较短时，也可用这种结构。

例如：It shocked me that Peter did not tell anybody where he was.
让我吃惊的是彼得没有告诉任何人他在哪里。

It does not interest me whether you go or not.
我对你去不去不感兴趣。

2.只用whether不用if引导主语从句.
二、主语从句与形式主语it
有时为了考虑句子平衡，通常在主语从句处使用形式主语it，而将真正的主语从句移至句末。

这分三种情况：
(1) 对于以连词that引导的主语从句，通常用形式主语代主语从句：
It’s a pity that he didn’t come. 很遗憾他没来。

It is important that he should know about this. 他必须知道此事。

It’s vital t hat we be present. 我们出席是至关重要的。

It was intended that you be the candidate. 大家的意图是让你当候选人。

It is important that this mission not fail. 这项使命不失败至关重要。

It is essential that a meeting be convened this week. 本周开一次会非常重要。

It is appropriate that this tax be abolished. 废除这个税是恰当的。

It’s unfair that so many people should lose their jobs. 竟有这么多人失业这是不公平的。

It’s amazing that she should have said nothing about it. 她竟未谈及此事令人惊讶。

It’s unthinkable that they should deny my request. 他们竟然拒绝我的请求，这是不可思议的。

That they should refuse to sign the petition required great courage. 他们拒绝在请愿书上签字这是需要很大勇气的。

(2) 对于以连接代词(副词)引导的主语从句，可以使用形式主语代主语从句，也可直接在句首使用主语从句：
Whether they would support us was a problem. 他们是否会支持我们还是一个问题。

It was a problem whether they would support us. 他们是否会支持我们还是一个问题。

It remains to be seen whether it will do us harm or good. 它对我们是利是害，还得看看再说。

(3) 对关系代词型what引导的主语从句，通常直接将主语从句放在句首。

如：
What we need is money. 我们需要的是钱。

What I want to know is this. 我想知道的就是这一点。

有时也可将助用形式主语。

如：
It is clear enough what he meant. 他是什么意思很清楚。

(4) 如果句子是疑问句，则必须用带形式主语it的结构：
Is it true that he is the girl’s father? 他是那女孩的父亲，是真的吗？
How is it that you are late again? 你怎么又迟到了？(from
三、连词that的省略问题
引导主语从句的连词that 有时可省，有时不能省，其原则是：若that引导的主语从句直接位于句首，则that不能省略；若that引导的主语从句位于句末，而在句首使用了形式主语it，则that可以省略：That you didn’t go to the talk w as a pity. 很遗憾你没去听报告。

(that不可省)
It was a pity (that) you didn’t go to the talk. 很遗憾你没去听报告。

(that可省)
Ⅰ．选择题：
1. _____ as much as one-fifth of all timber harvested is not used.
A. The estimate
B. The estimate
C. They are estimated
D. It is estimated that
2. _____ some mammals came to live in the sea is not known.
A. Which
B. Since
C. Although
D. How
3. _____ we have achieved is attributed to the guidance of our parents.
A. Whoever
B. Whatever
C. However
4. _____ wealthy does not necessarily mean that a man is greedy.
A. For the reason that he is
B. Just because he is
C. The reason of being
D. That he is
5. Although _____ happened in this developed country sounds like science fiction, it could occur e lsewhere in the world.
A. which
B. what
C. how
D. it
6. _____ she had forgotten to take her notebook.
A. That occurred to her
B. She occurred that
C. To her that occurred
D. It occurred to her that
7. I am sure that _____ she said is wrong.
A. which
B. all
C. this
D. what
8. We lost our way in the forest, and _____ made matters worse was that it was getting dark.
A. that
B. which
C. it
D. what
9. _____ some mammals came to live in the sea is not known.
B. Since
C. Although
D. How
10. _____ or not is still uncertain.
A. He’s coming
B. If he is coming
C. That coming
D. Whether he’s coming
11. It’s _____ he’ll be able to come.
A. doubt whether
B. doubtful
C. doubt it
D. doubtful whether
12. _____ he is at work in the heart of the big city or at home in the quiet suburb, Dick’s life is tie
d to machines.
A. Whether
B. Till
C. If
D. Unless
13. _____ he saw both surprised and frightened him.
A. That
B. When
C. What
D. Which
14. _____ is a spell of warm sunshine.
A. What do we all need.
B. What all we need
C. What we need
D. What we all need
15. _____ is a pity that he should feel so upset.
A. What
B. That
C. He
D. It
16. _____ a spoonful of soil can tell us so much about the structure and early history of the moon.
A. Remarkable
B. Quite remarkably
C. It is remarkable that
D. It is remarkable fact that
17. _____ you nominate will be elected.
A. Who
B. Whom
C. Whomever
D. That’s
18. _____ book you borrow must be returned within a week.
A. What
B. Which
C. Whichever
D. That’s
19. _____ of us gets home first starts cooking.
A. Who
B. Which
C. Whichever
D. Anyone
20. _____orders he gives are obeyed.
A. Whichever
B. Which
C. Whatever
D. What
21. ____ wants to stay in a hotel has to pay their own way. (浙江2008)
A. Anyone
B. The one
C. Whoever
D. Who
22. ____ matters most in learning English is enough practice.(2007 全国卷Ⅱ)
A. What
B. Why
C. Where
D. Which
23. ____ fashion differs from country to country may reflect the cultural differences from one aspect. (上海2002 春)
A. What
B. That
C. This
D. Which
24. ____ we’ll go camping tomorrow depends on the weather. (NMET 1996)
A. If
B. Whether
C. That
D. Where
【巩固练习】
1.__________________________________ hasn’t been decided yet.(pick)
谁将去接他还没有确定。

2.__________________________________ remains unknown.(finish)
我们是否能按时完成工作还不知道
3._____________________________________ is none of my business.(like)
你不喜欢他与我无关。

4._________________________________________ is being discussed.(abroad)
他将何时出国正在讨论之中。

5.____________________________ in learning English is enough practice.(matter)
英语学习中最重要的是足够的练习。

6.It worried her a bit ______________________________________________.(turn)
她的头发正在变白让她有些担忧。

7.After Yang Liwei succeeded in circling the earth, what our astronauts desire to do ______________________________. (walk) 杨利伟成功地环绕地球后，我们的宇航员所想做的是在太空漫步。

8. ________________________________________ should be punished.(break)
任何违法的人都应该被惩罚。

9.______________________________ we can learn four foreign languages at the same time.(seem)
我们能同时学四门外语似乎不可能。

10._______________________________ was that more than 90% of the students had been admitted to the key universities.
真题：1、The Foreign Minister said, “______ our hope that the two sides will work towards peace.”
A. This is
B. There is
C. That is
D. It is
2、 After Yang Liwei succeeded in circling the earth, _____ our astronauts desire to do is walk in space.
A. where
B. what
C. that
D. how
3、 ____ is not known yet.
A. When she has gone
B. Where she has gone
C. How did she leave
D. Why did she go
4、 ______ is unfit for the office.
A. It seems to me that
B. It seems to me that he
C. That seems he
D. That seems to him that
5、 _______man must fear when traveling in space is radiation from the sun.
A. Which
B. How
C. What
D. That
6、 _______ beat Xiao Wang black and blue is not known.
A. Whom
B. Whoever
C. Who
D. What
7、________matters much ________ the headmaster supports our activity.
A．It; whether B．What; whether C．As; that D．That; if
8、________ is known to us all is that the Chinese government has spared no efforts to protect people from fake food.
A．As B．It C．That D．What
9、________ Premier Wen Jiabao visited the United States led to the closer relationship between the two countries.
A．Which B．What C．That D．As
10、It is obvious to the students ________ they should get well prepared for their future.
A．as B．which C．whether D．that
11、It is uncertain________side effect the medicine will bring about，although about two thousand patients have taken it.
A. that
B. what
C. how
D. whether
12、The villagers have already known ______ we'll do is to rebuild the bridge.
A．this B．that C．what D．which
13、It is still under discussion________the old bus station should be replaced with a modern hotel or not.
A．whether
B．when
C．which
D．where
14、________ Barbara Jones offers to her fans is honesty and happiness.
A. Which
B. What
C. That
D. Whom
15、It was never clear ________ the man hadn't reported the accident sooner.
A. that
B. how
C. when
D. why
I. 用适当的词填空，使句子意思完整。

1. ______ he didn’t attend the meeting yesterday wasn’t quite clear.
2. The Foreign Minister said, “It is our hope ______ the two sides will work towards peace.”
3. ______ team will win the match is still unknown.
4. ______ comes to the party will receive a present.
5. ______ Mary has left is still a question.
6. It’s reported ______ three people were killed in the accident and five were hurt badly.
7. ______ he solved the problem successfully interested all of us.
8. We usually think ______ we can’t get seems better than what we have.
9. It is a fact ______ English is being accepted as an international language.
10. ______ is to be sent there to solve the problem hasn’t been decided.
II. 下列各句中均有一处错误，请改正。

1. That the old man’s son wanted to know was where the gold had been hidden.
2. It is reported when China has successfully sent Shenzhou VI spaceship into space.
3. If he can finish his task on time is of great importance.
4. Whether the 2008 Olympic Games will be held in Beijing excited the whole nation.
5. After Yang Liwei succeeded in circling the earth, which our astronauts desire to do is walk in space.
6. Whatever leaves the room last ought to turn off the lights.
7. Why they will solve the serious problem today has not been decided.
8. When will win the English competition is still a problem.
9. How our spring sports meet will be held or not this week is not known yet.
10. It’s strange when he should have gone away without telling us.
1. Light travels faster than sound is common knowledge.
2. If she’s coming or not doesn’t matter much.
3. That the professor said is of great importance.
4. Where will the trees be planted has not been decided.
5. No matter who breaks the rule will be punished.
6. When and where the meeting will be held still remain a question.
7. What were your problems a year ago has now become mine.
8. It was requested that everyone made a speech at the meeting.
1、D。

此句为it 放在句首作形式主语，真正的主语是that 引导的从句。

2、B。

考查主语从句。

从句中动词do缺少宾语，故选what，what引导的从句在句中作主语。

3、B
4、B
5、【解析】C. 考查主语从句，并在主语从句中作fear的宾语what的用法。

6、C
7、A解析：it 是形式主语，真正的主语是whether 引导的从句。

句意：校长是否支持我们的活动很重要。

故选A项。

8、D解析：what 在这里引导主语从句，选D项。

此题要注意分析句子结构，如果题目改为：①________ is known to us all, the Chinese government has spared no efforts to protect people from fake food.该句空处应用As, As 引导非限制性定语从句；
②________ is known to us all that the Chinese government h as spared no efforts to protect people from fake food.该句空处则应用It, It 作形式主语。

9、C解析：句意：温家宝总理访问美国让两国之间的关系更加密切。

“That Premier Wen Jiabao visited the United States”是主语从句，that 在从句中只起连词作用，不作句子成分，本身没有词义，但是不可省略。

10、D解析：it是形式主语，代替后面的主语从句。

主语从句结构完整，故用that引导。

that 在主语从句中不作成分，但不能省略。

11、B解析：句意：尽管大约有两千名病人已经服用了这种药物，但是它会产生什么样的副作用现在还不能确定。

根据句意可知应该选择B项引导主语从句。

what在这里实际上是作为形容词来修饰后面的“side effect副作用”。

一起作从句中bring about的宾语。

12、C解析：句意：村民们已经知道我们要重建这座桥。

分析句子结构可知，known后跟宾语从句，省略了连接词that。

此宾语从句中又包含一个主语从句，主语从句中do缺少宾语，所以用what引导该从句作整个宾语从句的主语，答案为C项。

13、A解析：whether“是否”；when“当……时候”；which“哪一个”；where“哪儿”。

句意：旧车站是否要被现代化的旅馆所代替仍在讨论中。

根据句意可知选A项。

14、B解析：句意：“巴巴拉·琼斯给予她粉丝的是诚实和快
乐。

”“________Barbara Jones offers to her fans”在句中作主语，为主语从句。

what引导主语从句并且在从句中作offers的宾语，故选B项。

which表示“哪一个”；whom表示“谁”。

均不符合句意。

15、D解析：句意：这名男子没有早点报告这次事故的原因根本没有搞清楚。

it在句中是形式主语，真正的主语是why引导的主语从句。

16、C
17、C
18、 D
19、A
【答案】
1.Who will pick him up
2.Whether we can finish the work on time
3.That you don’t like him
4.When he will go abroad
5.What matters most
6.that her hair was turning grey
7.walk in space
8.Whoever/Anyone who breaks the law
9.It seems impossible that
10. What made the school proud
Key:
I．1. Why 2. that 3. Which 4. Whoever
5. Whether
6. that
7. How
8. what
9. that 10. Who
II．1. That →What 2. when →that
3. If →Whether
4. Whether →That
5. whi ch →what
6. Whatever →Whoever
7. Why →How 8. When →Who
9. How →Whether 10. when →that
1. 在句首加That（并将Light改为light）。

that虽无词义但引导主语从句位于句首时不能省略。

2. 将If改为Whether。

if, whether都可表示“是否”，但if不能引导位于主句之前的主语从句，它可以引导位于主句之后带有形式主语it的主语从句。

3. 将That改为What。

that引导主语从句时无词义。

What the professor said表示“教授所说的”。

4. 将will置于trees之后。

主语从句要用陈述句语序。

5. 将No matter who改为Whoever。

引导让步状语从句时二者可互换，但引导名词性从句时
只能用whoever。

6. 将remain改为remains。

主语从句表示单一概念时，谓语要用单数形式。

7. has要改为have。

主语从句表示复数概念时，谓语要用复数形式。

8. 将made改为（should）make。

在“It is requested / ordered / suggested + that从句”中，从句要用虚拟语气，即谓语用“should + 动词原形”，should可省略。