主语从句详细讲解及综合练习

主语从句
一、概念：在复合句中起主语作用的从句叫主语从句。

（一）连接词
从属连词：that、whether；
关系代词：who, what, which , whom, whose, whatever, whoever, whomever, whichever；
关系副词：when, where, how, why, however, whenever, wherever等；
例：What he said is true.
That you don’t like him is none of my business.
Whether the football game will be played depends on the weather.
主语从句的时态：不受主句的时态影响和限制。

（1）______ he finished writing the composition in such a short time ______(惊讶) us all.
（2）______we will go for an outing tomorrow ______（remains，remained）unknown.
（3）______ will be our monitor ______(be) decided yet.
（4）______we must study for ______ (be) a question of great importance.
（5）______ caused the accident ______（remains，remained）unknown.
（6）______ you did ______ (be)right.
（7）______ watch ______(be) lost is unknown.
（8）______we need ______(be) time.
（9）______ we need ______(be) good doctors.
小结:
（1)主语从句的时态：不受主句的时态影响和限制。

（2)连词位于句首不能省略（3)主语从句大多数情况下视为三单,但也有例外,如例9
1. 从属连词that，whether引导的主语从句。

从属连词that，whether在主语从句中的作用只是引导主语从句，在从句中不担任成分，不能省略。

例：__________ they will go is certain.
__________ she will come or not is still a question.
__________ she's coming or not doesn't matter too much.
2. it作形式主语引导主语从句。

如果主语从句太长，为避免句子结构头重脚轻，我们可用it作形式主语，而把主语从句放在主句谓语部分之后。

That引导的主语从句可用it代替，that 不可省略。

用作it作形式主语的结构：
（1）It is/was +形容词+that 从句
It’s natural that…很自然……It’s obvious that …显而易见……
It’s fortunate that …幸运的是It’s (im)possible…（不）可能……
It’s unlikely that…不可能It’s strange that…奇怪的是……
（2）It is/was +名词+that 从句
It’s a pity that…遗憾的是……It’s a fact that …事实是……
It’s good news that…是好消息……It’s a wonder that…不足为奇……
It’s an honour that…非常荣幸……It’s a shame that…真是可耻……
It’s common knowledge that …是常识…
（3）It +不及物动词+that 从句
It seems that…似乎……It happened that…碰巧……
It appears that…看来……It turns out that…结果……
（4）It is/was +过去分词+that 从句
It’s not known that………不得而知It’s said that…据说……
It’s reported that…据报道……It’s decided that…尚未决定
It’s believed that…据认为……It’s announced that…据宣布……
It suddenly struck me (occur to me that…我突然想到（感觉到）……
（5）其他
It doesn’t matter …是无关紧要的
It makes no difference …毫无区别……
It is of little consequence that…无关紧要
It is a pity __________ she has made such a mistake. 她犯这样的错误是令人遗憾的事。

It's strange __________ he didn't come yesterday. 他昨天没来是很奇怪的。

It is reported __________ the number of wild animals in Africa is decreasing.
据报导非洲野生动物的数量正在减少。

It is said __________ there was a terrible plane crash this morning.
据说今天早上有一起可怕的飞机坠毁事故。

1）主语从句在句首时，必须由连注意:
接词引导，不能省略这些连接词；但是如果用it做形式主语，而把主语从句放在句末时，从属连词that可以省略。

误：They should like each other is natural.
正：That they should like each other is natural.
正：It is natural that they should like each other.
2)如果主语从句放在句首，不能用if引导，但是如果用it 做形式主语，而把主语从句放在句末时，也可以用if引导.
误：If Mary really heard him is really doubtful.
正：It was doubtful if Mary really heard him.
4) . 用于It is important / natural / necessary / impossible that...句型中, 主语从句应使用虚拟语气, 谓语动词用\“should + 动词原形\”的形式, should有时可以省略。

5) 在It + be+suggested/advised/ordered/requested/ insisted/required 中, that从句的谓语也应该用\“should + 动词原形\”的形式, should有时可以省略。

Does _______ matter if he can't finish the job on time ?A. this B. that C. he D. it
_______ is a fact that English is being accepted as an international language.
A. There
B. This
C. That
D. It
It is necessary that a college student _______ at least a foreign language.
A. masters
B. should master
C. mastered
D. will master
_______ is known to everybody, the moon travels round the earth once every month.
A. It
B. As
C. That
D. What
3、由关系代词引导的主语从句。

（1）关系代词who, what, which, whom, whose, whatever, whoever, whomever, whichever等，引导主语从句时，它们分别在从句中担任主语、宾语或定语，不能省略。

__________ leaves the room last ought to turn off the lights. 走得最晚的应当关灯。

__________ you have done might do harm to other people. 你的行为可能伤害别人。

__________ he said at the meeting astonished everybody present.
他在会议上的发言时所有入会者吃惊。

__________ made the long distance call is not important. 谁打的长途电话并不重要。

（2）what引导主语从句“……的东西/事情”时，可用来表示the thing(s)which这种意思，引
导从句，表示一样东西与一件事情，这种用法的what称为关系代词型what，who，whom，which，what可以和ever构成合成词，和what一样引导从句，ever起强调作用。

这些关系词在句子中充当成分，所以不能省略。

此类主语从句不能用形式主语it引导。

__________ (=The thing which I need) is a mobile phone.
我所需要的是一部移动电话。

__________ leaves the office (=Any one who leaves the office)should tell me.
无论是谁离开办公室都应该告诉我。

4、关系副词引导的主语从句。

连接副词有when, where, why, how, however, whenever, wherever等引导主语从句时，它们在从句中担任状语，不能省略。

此类主语从句可以转换为以it作形式主语的句子。

__________ he didn't come here is not clear to anyone. 他为什么没来谁也不清楚。

__________ a telephone works is a question which not everyone can answer.
电话是怎样工作的，这个问题并不是每个人都能回答。

__________ she has gone is not known yet. 她去了哪儿，还不知道。

__________ they will start has not been decided yet. 他们何时动身还未定下来。

__________ he did it didn't concern me. 他为什么做这件事与我无关。

5、主语从句不可位于句首的四种情况。

（1）含主语从句的复合句是疑问句、感叹句时，主语从句不可提前，用引导词it作形式主语。

Is it really true that he has gone abroad? 他真的出国了吗？
How surprising it was that he failed in the exam! 真令人惊奇，他考试没有及格！
（2）It is said, reported, …结构中的主语从句不可提前。

It’s said that the play is very interesting. 据说戏剧很有趣。

It’s reported that the highway will be opened to traffic next week.
据报道，高速路下周通车。

（3）It happens, occurs…结构中的主语从句不可提前。

It occurred to her that she had forgotten to lock the door. 她突然想起忘了锁门。

It happened that I met him in the street. 我恰巧在大街上遇到了他。

（4）It doesn’t matter how, whether or not…结构中的主语从句不可提前。

It doesn’t matter whether he likes it or not. 他喜欢与否无关紧要。

It doesn’t matter how he will come. 他怎么来不重要。

6、it作形式主语与it引导强调句的比较。

it作形式主语代替主语从句，主要是为了平衡句子结构（特别是谓语较短时），主语从句的连词没有变化。

而it引导强调句则是对某一句子成分的强调（这一成分可以是词、词组或句子），其结构是“It is(was)+ 强调成分+that”。

无论强调什么成分，都要求用连接词that(强调人时可以用who代替)。

It is certain that she will succeed.她会成功是肯定的。

（主语从句）
It is in New York that I met him.是在纽约我见到了他。

（强调句）
7. what 与that 在引导主语从句时的区别
what 引导主语从句时在句时在从句中充当句子成分，如主语．宾语．表语，而that 则不然。

例如：
1) What you said yesterday is right.
2) That she is still alive is a consolation.
That 只起连接作用,不做成分
1. _______ you have done might do harm to other people. A. That B. What C. Whether D. How
2. __ he said at the meeting astonished everybody present.
A. What
B. That
C. The fact
D. The matter
3. ___we can't get seems better than ___we have.
A. What; what
B. What; that
C. That; that
D. That; what
4. It worried her a bit _______ her hair was turning grey. A. while B. that C. if D. for
5. _______ you don't like him is none of my business.A. What B. Who C. That D. Whether
8. 主语从句需注意的问题
(1)主语从句中用陈述语序
What she is afraid of is their taking her to Paris. ( What is she afraid of …Wrong )
(2)主语从句后谓语动词用第三人称单数
That they haven’t phoned is strange.
(3)that引导的主语从句中，that不可被省略
That price will go up is certain.
(4)引导主语从句，放在句首时，不能用if，只能用whether。

Whether we will hold a party in the open air tomorrow depends on the weather.
_______ the 2000 Olympic Games will be held in Beijing is not known yet.
A. Whenever
B. If
C. Whether
D. That
_______ we'll go camping tomorrow depends on the weather. A. If B. Whether C. That D. Where
(5)whatever / whoever的功用
whatever, whoever在主语从句中不含疑问意义。

它引导主语从句，并在从句中作主语、宾语、表语等。

whatever = anything that; whoever = anyone who。

要注意和whatever, whoever引导的让步状语从句的区别。

如：
Whoever breaks the law should be punished. （主语从句）
（＝Anyone who breaks the law should be punished. ）
Whoever breaks the law, he should be punished. （让步状语从句）
（＝No matter who breaks the law, he should be punished. ）
anyone与the person皆不能引导从句.
___ leaves the room last ought to turn off the lights.A. Anyone B. The person C. Whoever D. Who It is generally considered unwise to get a child _______ he or she wants.
A. however
B. whatever
C. whichever
D. whenever
练习：填入适当的连接词
1. It is likely _____ he is the winner of this game.
很可能他是这场游戏的胜利者。

2. ______ she bought so many dictionaries is not clear.
= It is not clear _____ she bought so many dictionaries.
不清楚她为什么买这么多字典。

3. ________ he was admitted into Beijing University made his teachers and parents happy. 他考上了北大，这让他的老师和父母很高兴。

4. It’s a pity________ you can’t attend my birthday party.
很可惜你不能参加我的生日聚会。

5. _________ we will build a new high school hasn’t been decided.
我们是否要建新高中还没决定呢。

6. __________ breaks the law should be punished. 不管谁违法都应该受到惩罚。

7. It is necessary ______ the problem (should) be solved at once.
很有必要立刻解决这个问题。

8. ________ he was born is unknown. 他生于何时还不知道。

9 It is possible _______ he has stolen the car. 很可能他偷了小车。

10. _______ has broken the glass is unknown. 谁打破了玻璃现在还不知道。

11. _______ he wants is all here. 他所要的东西都在这里。

12. _______ he worked it out is still a secret.
他是如何把它做出来的还是一个秘密。

13. _______ they makes in this factory are TV sets.
他们在工厂里所做的东西就是电视机。

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

15. ________ you want is yours. 你要哪个哪个就是你的。

16. ________ we need is money. 我们需要的是钱。

17.________ we arrive doesn’t matter. 什么时候到没有关系。

18. ________ it was done was a mystery. 这是怎样做的是一个谜。

19 ________ this happened is not clear to anyone.
这件事怎样发生的，谁也不清楚。

20. ________ I spend my summer is no business of yours.
我在哪里过暑假不关你的事。

练习一
1.________ makes mistakes must correct them.
A. What
B. That
C. Whoever
D. Whatever
2. It worried her a bit ____ her hair was turning grey.
A. while
B. that
C. if
D. for
3.When and why he came here ________ yet.
A. is not known
B. are not known
C. has not known
D. have not known
4. ________ is no reason for dismissing her.
A. Because she was a few minutes late
B. Owing to a few minutes late
C. The fact that she was a few minutes late
D. Being a few minutes late
5. ________ Tom liked to eat was different from ________.
A. That…that you had expected
B. What …that you had expected
C. That…what you had expected
D. What…what you had expected
6.________ we go swimming every day ________ us a lot of good.
A. If...do
B. That...do
C. If...does
D. That...does
7.It ________ Bob drives badly.
A. thinks that
B. is thought what
C. thought that
D. is thought that
8.It's uncertain ________ the experiment is worth doing.
A. if
B. that
C. whether
D. how
9.________ the boy didn't take medicine made his mother angry.
A. That
B. What
C. How
D. Which
10.____ we can't get seems better than ____ we have.
A. What, what
B. What, that
C. That, that
D. That, what
11.____ you don't like him is none of my business.
A. What
B. Who
C. That
D. Whether
12..____ we'll go camping tomorrow depends on the weather.
A. If
B. Whether
C. That
D. Where
13._________is going to do the job will be decided by the Party committee.
A. That
B. Why
C. How
D. Who
14._______we'll finish translating the book depends on the time.
A. When
B. Why
C. What
D. That
15.______he won't go there is clear to all of us.
A. How
B. What
C. Why
D. This
16.______the house will be built will be discussed at tomorrow's meeting.
A. If
B. Where
C. That
D. What
17. ._______you come or not is up to you.
A. What
B. If
C. Why
D. Whether
18.._______makes mistakes must correct them.
A. Who
B. Anyone
C. Whoever
D. Anybody
19.._______team will win the match is a matter of public concern.
A. Which
B. That
C. If
D. How
20..________leaves the room last ought to turn off the lights.
A. Anyone
B. The person
C. Whoever
D. Who
练习二
1. has helped to save the drowning girl is worth praising.
A. Who
B. The one
C. Anyone
D. Whoever
2. It was he said disappointed me.
A. what ; that
B. that; that
C. what; what
D. that; what
3. we’ll go camping tomorrow depends on the weather.
A. If
B. Whether
C. That
D. Where
4. he said at the meeting surprised everybody present.
A. What
B. That
C. The fact
D. The matter
5. was to return to school.
A. That really interested him
B. What really interested him
C. Which really interested him
D. That interest him really
6. makes mistakes must correct them.
A. What
B. That
C. Whoever
D. Whatever
7._______ he made an important speech at the meeting was true.
A. That
B. Why
C. What
D. How
8. ________we’ll go camping tomorrow depends on the weather.
A If
B Whether
C That
D Where
9. It worried her a bit ______ her hair was turning gray.
A. whether
B. That
C. what
D. when
10.What I say and think ___ none of your business.
A. is
B. are
C. has D have
11. Does _______ matter if he can't finish the job on time?
A. this
B. that
C. he
D. it
12. It worried her a bit _______ her hair was turning grey.
A. which
B. that
C. if
D. for
13. _______ is a fact that English is being accepted as an international language.
A. There
B. This
C. That
D. It
14. _______ what they told me really true?
A. Has
B. Is
C. Does
D. Have
15. It matters little _____ a man dies, but ____ matters much is ____ he lives.
A. how; what; how
B. how; it; how
C. why; it; why
D. that; what; that
16. ____ she couldn't understand was ____ fewer and fewer students showed interest
in her lessons.
A. What; why
B. That; what
C. What; because
D. Why; that
17. It is pretty well understood _______ controls the flow of carbon dioxide in and out
the atmosphere today.
A. that
B. when
C. what
D. how
18. _______ fashion differs from country to country may reflect the cultural
differences from one aspect.
A. What
B. That
C. This
D. Which
19. -What made her parents so angry?
- _______ she had failed in the examination.
A. As
B. Because
C. Since
D. That
20. _______ we'll go camping tomorrow depends on the weather.
A. If
B. Whether
C. That
D. Where
21. -Do you remember _______ he came?
-Yes, I do. He came by car.
A. how
B. when
C. that
D. if
22. It was a matter of _______ would take the position.
A. who
B. whose
C. whom
D. whomever
23. -I drove to Zhuhai for the air show last week.
-Is that _______ you had a few days off?
A. why
B. when
C. what
D. where
24. I read about it in some book or other, does it matter _______ it was?
A. where
B. what
C. how
D. which
25. It is necessary that a college student _______ at least a foreign language.
A. masters
B. should master
C. mastered
D. will master
例题：that surprised whether remains who hasn't been whom is what remains whatever is whose was what is what are
what that练习1-5 BAABC
whatever whoever练习CB
it 练习DDBA
练习一[参考答案] 1-10 CBACD DDCAA 11-20 CBDAC BDCAC
练习二Key: 1-10 D A B A B C A B B A 11-15 DBDBA 16-20 ACBDB 21-25 AAADB。