(完整版)名词性从句

名词性从句

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、表语从句、宾语从句和同位语从句。二．名词性从句连接词

四．if, whether的区别

1.引导主语从句时，如果主语从句放在句首，只能用whether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.

2.引导宾语从句时常放在动词know, ask, care, wonder之后，if和whether均可。少数动词，如: leave, put, discuss, doubt后的宾语从句常用whether. 。

3.在介词后面的宾语从句中，在表语从句、同位语从句中，表“是否”，只能用whether；

4.whether和if都可以和or not连用,但是whether 之后可以直接跟or not,而if不可以。I do n’t know whether or not I will stay.（只能用whether）

5.在不定式前只能用whether.

如：I can’t decide whether to stay. 我不能决定是否留下。

五．与“命令、要求、建议”等相关的名词性从句中通常用虚拟语气，虚拟语气的构成是“should＋动词原形”或省去should，直接用动词原形。

六．名词性从句以考查引导词为主，同时考查时态，语序，与其它从句的区别以及混同虚拟语气的考查。

一．主语从句

1.主语从句定义：在复合句中充当主语的句子叫做主语从句。

That he will succeed is certain.

Whether wild life can be well protected is of great importance.

Who will go makes no different.

Which kind of food is the best is still not certain.

What is needed for the space trip is careful preparation.

Whoever comes is welcome.

How we can help the twins will be discussed at the meeting.

When they’ll start the project has not been decided yet.

Where he hid the money is to be found out.

Why dinosaurs died out remains a puzzle.

2.主语从句引导词按照在句中是否做成分主要分为三类：连词that、whether、if 连接代词、连接副词。

（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,引导主语从句的连词that 的省略：若that引导的主语从句直接位于句首，则that不能省略；若在句首使用了形式主语it，that引导的主语从句置后，则that 可以省略。

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。

That you didn’t go to the talk was 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) （2）由连词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。whether 可以和or not连用。

Whether it will do us harm remains to be seen. 是否对我们有害还要看一看。Whether they would support us was a problem.他们是否会支持我们还是一个问题。Whether she is coming or not doesn’t matter too much.她来不来都无关紧要。

（3）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.

Whether Mary really heard him is really doubtful.（对）

It was doubtful if Mary really heard him.（对）

If Mary really heard him is really doubtful.（错）

（4）连接代词引导的主语从句：连接代词who, whose, whom, which, what, whoever, whomever, whichever, whatever，在句子起名词性作用，担当一定成分。不能省略。

Who killed the scientist remains a question.

Whom she borrowed money from still puzzled him.

Which side will win is not clear.

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 he did is right.

Whoever breaks the law will be punished. (主语从句)

= Anyone who breaks the law will be punished. (定语从句)

比较：Whoever breaks the law，he should be punished.(让步状语从句)

= No matter who breaks the law，he should be punished. (让步状语从句)

（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。)

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。

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

3.主语从句注意事项

（1）为了避免主语冗长,句子头重脚轻,经常用it 做形式主语,而将主语从句置后（尤其是当谓语较短时）。

①That 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。

②Whether 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.

③When 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。（2）如果句子是疑问句，则必须用带形式主语it的结构

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？

（3）连接代词What引导的名词性从句

①what引导主语从句时，常常翻译为“所…….的”或“…..的事物/东西/人/样子/地方等”此时无疑问含义。What在从句中作主语，宾语。

What you need is a good-sized canvas bag.

What make the river more beautiful are the lotus(荷花) plants growing in the water.

②what引导主语从句时，谓语动词常与其后的作表语的名词一致。

What you left are only several old books.

What you said is of great importance.

③what引导主语从句常见句型。

What makes this shop different is that it offers more personal service.

（4）Who, whom, which, what和ever构成合成词，ever起到强调作用，此类引导词引出的主语从句一般不能用形式主语it引导。

（5）单个主语从句作主语时，谓语动词用单数形式。如果是两个或两个以上的主语从句作主语，谓语动词则用复数形式。

4.固定用法（借助形式主语it，主语从句不能提前）和译法

（1）It is +名词+that从句

It is a fact that…事实是……

It is good news that ………是好消息

It is a question 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+ that从句

It is necessary 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.

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。

用于It is important / natural / necessary / impossible that...句型中, 主语从句应使用虚拟语气, 用“should + 动词原形”的形式, should有时可以省略。

It is natural that they （should）like each other.

（3）It is +过去分词+that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 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。

在It + be + suggested/advised/ordered/requested/ insisted/required 中, 应使用虚拟语气,即that从句的谓语用“should + 动词原形”的形式, should有时可以省略。

It is suggested that we should eat more vegetable and do more exercise.

（4）It + 不及物动词或短语+ that 从句( happen, doesn’t matter ,turn out）。如：It happened that I saw him yesterday.碰巧我昨天看见他了。

It does not matter whether 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。

（5）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。

二．表语从句

1.定义：在复合句中，如作表语的是一个从句，该从句被称为表语从句。

Here wish is that she could lose weight soon.

The question is whether it is worth doing.

It looked as if it was going to snow.

The problem was who could do the work.

That is what he is worried about.

His trouble is where he can find a new job.

The problem is how he can get food and clothing.

That was why the brothers wanted to make a bet.

2.表语从句的构成：主语+ 系动词+ 引导词+ 句子

3.常见的系动词

（1）be（am, is, are, was, were)

（2）feel , seem , look, appear ,sound, taste , smell

（3）stand , lie , remain ,keep, stay

（4）become ,get , grow , turn ,go ,come, run, fall

（5）prove, turn out

4.表语从句的连接词：

接词：that / whether /as if /as though / because (if不引导表语从句)

连接代词：who / whom / whose / which / what

连接副词：when / where / why / how

(1) 从属连词that：that 在表语从句中不担任句子成分，无实际意义，一般不能省略

（2）whether在表语从句中表“是否”但不充当句子的成分。if 不能引导表语从句。如:

The question is whether it is worth doing.

What the doctor really doubts is whether my mother will recover from the serious disease soon.

（3）as if/as though引导的表语从句如果是事实，就用陈述语气，如果与事实不符，就用虚拟语气(主句一般现在时从句就用过去式，be的话变成were。主句是过去式，从句用过去完成时)。

It looks as if he were her own father. (与事实不符)

It was as though he were mad. (与事实不符)

Dark clouds are gathering. It looks as if it’s going to rain.

（4）because引导表语从句通常只用于“This/That/It is because…”结构中。My anger is because you haven’t written to me for a long time.

（5）连接代词who, whom, whose, what, which, whoever, whatever, whichever引导的表语从句。

The problem is who we can get to replace her.问题是我们能找到谁去替换她呢。That was what she did this morning on reaching the attic.那就是她今晨上了阁楼干的。

I read about it in some book or another, but what I don’t know is which (book) it is. what 在表语从句中充当主语、宾语或表语表示“什么”，“所…….的”或“…..的事物，东西，人，样子，地方等”

The question is what caused the accident.

That mountain is no longer what it used to be .

What he told you was what had been discussed at the meeting.

（6）连接副词where, when, how, why除在句中起连接作用外，在从句中还充当时间、地点、方式、原因状语，本身具有词义。

That’s where I can’t agree with you.

This is why Sara was late for the meeting.

This is how they overcome the difficulties.

My strongest memory is when I attended an American wedding.

The question is how he did it. 问题是他是如何做此事的。

That is where he was born.那就是他出生的地方。

5. 表语从句注意事项

（1）that, why 与 because 引导表语从句时的区别

虽然三者均可引导表语从句，但 that 没有词义，而 why 和 because 有自

己的意思；另外，虽然 why和 because 都可引导表语从句，但前者why 强调结果，后者because强调原因。如：

?The reason was that you don’t trust her.原因是你不信任她。

?The fact is that they are angry with each other. 事实是他们生彼此的气。

?He was ill. That’s why he was sent to the hospital.他病了，所以被送到医院来。

?He was sent to the hospital. That’s because he was ill.他被送到医院，是因为

他生病了。

（2）reason 做主语时，表语从句只能用that引导, 不能用why 引导。句型结构为：The reason is that……

或者The reason (why…/for…)is /was that….（表语从句常用常考句型）

The reason why he was late was that he missed the train by one minute this morning （当主语是reason时，reason后面的表语从句只能用that引导,而不能用because 或者why. 但reason后面的定语从句可以用why或者that 引导。）

The reason why he was late for school was that he got up late．

The reason that he gave for his absence was that he was ill.

（3）表语从句的另一常用句型：名词主语＋be＋that从句

The fact is that I was in the garden when the robbery happened.

作主语的名词通常有表示事实、真理的名词fact, truth

或表示看法观点的名词idea, opinion, belief, view, feeling, suggestion, plan等。

如果是suggestion, proposal, advice, requirement 等词后的表语从句要用虚拟语气（should）do。

三．宾语从句

1．定义：在复合句中充当宾语的句子叫做宾语从句。

They know that the habit will kill them.

He asked whose spacesuit it was.

Will you please tell me how I can keep fit and healthy?

Pay attention to what the doctor said, will you?

宾语从句分为动词（包括动词，动词短语，动词不定式，动词ing）的宾语从句和介词的宾语从句。

2. 动词的宾语从句。

①动词短语后的宾语从句

I have found out that all the tickets for the concert have been sold out.

②动词ing后的宾语从句

Not knowing what he should do, he began to cry.

③双宾语，直接宾语由从句充当

He told me that he would go to the university.

④形式宾语：动词find, feel, consider, make, believe等后面有宾语补足语的时候，则用it作形式宾语，而将宾语从句后置。此时that不能省略。

I feel it a pity that I haven’t been to the get-together. 我没去聚会,感觉非常遗憾.

He has made it clear that he will not give in.他已表明他不会屈服。

I think it necessary that we take plenty of hot water every day.

我认为每天多喝开水是有必要的.

⑤有些动词带宾语从句时需要在宾语与从句前加it ，这类动词主要有：take ,have, like, dislike, love, hate, appreciate等，后常跟that, if 或when从句。We take it that you will agree with us. 我们认为你会同意我们的。

He will have it that our plan is really practical. 他会认为我们的计划确实可行。

I hate it when they with their mouths full of food. 我讨厌他们满嘴食物时说话。

⑥动词doubt后的宾语从句：肯定句用连词whether/if引导，否定，疑问句用连词that引导。

⑦be sure后的宾语从句：肯定，疑问句中用that, 否定句中用连词whether/if引导

3．介词的宾语从句

We are talking about whether we admit students into our club.

我们正在讨论是否让学生加入我们的俱乐部.

Are you sorry for what you've done? 你为你所做的一切感到内疚吗？

He was deeply displeased by what had occurred that day.他对那天发生的事感到很不快。

I walked over to where she sat. 我走向她坐的地方。

The new book is about how Shenzhou 6 manned spaceship was sent up into space.

这本新书是关于神州6号载人航天飞船是如何升入太空的.

The boy is interested in whatever he saw here.

The first prize should go to whoever writes best.

注意：

①连词that引导的名词性从句很少作介词的宾语，只用在except, but, in, besides

等之后才用。其他一些介词的宾语从句如果由连词that引导，则需用it先行一步，作形式宾语。

I could say nothing but that I was angry. 我无话可说，只是感到生气。

I know nothing about him except that he is from the south.

He is a good student except that he is careless.他是一个好学生，只是有点粗心。When you start the engine, you must see to it that car is in neutral.

开启发动机时, 一定要使汽车的离合器处于空挡位置。

You may rely on it that I shall help you. 你可以指望我会帮助你的。

②介词后的宾语从句一般不用which和if引导，要用whether和what。

4.引导宾语从句的关联词有三类：

(1) 从属连词that。如：

He told us that he felt ill. 他对我们说他感到不舒服。

I know he has returned. 我知道他已经回来了。

注：that在引导宾语从句时也并不是任何情况下都可以省略。在以下情况下，that 不能省略。

①and连接两个宾语从句，放在and后面的that宾语从句，that不能省略。Everybody could see what happened and that Tom was frightened.

大家都会看出所发生的事情并知道Tom非常害怕。

②主句谓语动词与that从句之间有插入语，that不可省略

We decided, in view of his special circumstances, that we would admit him for a probationary period.鉴于他的特殊情况，我们决定应允他一段试用期。

③that引导的宾语从句作介词宾语时，that不能省略

I know nothing about him except that he is from the south.

对他我一无所知，只知道他是南方人。

④有it作形式宾语时不能省

I hate it when they with their mouths full of food. 我讨厌他们满嘴食物时说话.

He is a good student except that he is careless.他是一个好学生，只是有点粗心。

I feel it a pity that I haven’t been to the get-together. 我没去聚会,感觉非常遗憾.

(2)从属连词if/whether。如：

I doubt whether he will succeed. 我怀疑他是否会成功。

I don’t know if you can help me. 我不知道你能否帮助我。

①if和whether在作“是否”解时,引导宾语从句常放在动词know, ask, care, wonder, find out等之后,介词后一般用whether不用if 引导。

②if和whether引导的宾语从句可以互换使用，但whether常和or not连用，if 一般不与or not连用。如：I wonder whether it is true or not. 我不知它是真是假。

③避免歧异时,我们常用whether而不用if.

(3)连接代词who, whom, whose, what, which, whoever, whatever, whichever

连接副词where, when, how, why。如：

Have you decided which subject you are going to choose?

He asked me how soon we would finish the work.

I wonder what he’s writing to me about. 我不知道他要给我写信说什么事。

I will tell you why I asked you to come. 我会告诉你我为什么要你来。

（4）what引导的宾语从句

①翻译为“什么，什么样的”，有疑问含义

I wonder what has happened to him.

May we ask what you are doing in this country and what your plans are?

②翻译为“所…….的”或“…..的事物，东西，人。样子，地方等”此时无疑问含义。What在含以上相当于the thing(s) that

All that

先行词+that

I am interested in what you are doing now.宾语从句

= I am interested in the thing(s) that you are doing now.定语从句

I will do what I can to help you. 宾语从句

=I will do all that I can to help you.

5.宾语从句注意事项。

(1)宾语从句的时态变化规律：当主句是一般现在时态时，从句可根据需要用任何时态。当主句是一般过去时态时，从句只能使用过去范围内的任何时态。但客观真理除外。

（2）宾语从句的语序用陈述语序：连接词+主语+谓语+其他成分。

（3）宾语从句中的虚拟语气：在表示建议suggest 、advise、propose; 要求demand 、desire、request；决定decide; 命令order、command、require; 坚决主张insist; 等动词后跟宾语从句，运用虚拟语气，即用（should）+v．如：

I suggested that you（should）study hard．

He ordered that we should go out at once．

（4）宾语从句的否定转移。在think, believe, suppose, expect等动词后的宾语从句，有时谓语尽管是否定意思，却不用否定形式，而将think等动词变为否定形式。如：

I don’t think you are right. 我认为你错了。

I don’t believe they have finished their wor k yet. 我相信他们还未完成他们的工作。

I don’t suppose he cares, does he? 我想他不在意，是吗？

四. 同位语从句

1.概念：同位语从句就是在复合句中作名词的同位语的从句。

The fact that women can work as well as men is clear.

We were very excited at the news that our team had won.

Henry Adams made a promise that he would not open the letter until 2 o’clock.

I have no idea when Chaplin’s film will be on again.

同位语从句一般跟在某些表示抽象概念的名词后面，用以说明名词所表示的具体内容。常跟同位语从句的名词主要有：idea，news，fact，promise，answer，belief，condition．doubt，fear，hope，problem，proof，question，reply，report，suggestion，thought，truth，message，word（消息），suggestion，，possibility等等。

I heard the news that our team had won．我听到了我们队获胜的消息。

I’ve come from Mr wang with a message that he won’t be able to see you this afternoon. 我从王先生那里来，他让我告诉你他今天下午不能来看你了。

He must answer the question whether he agrees to it or not.

他必须回答他是否同意这样一个问题。

▲有时同位语从句可以不紧跟在抽象名词后面，而被别的词隔开。

The thought came to him that maybe the enemy had fled the city.

他突然想起可能敌人已经逃出城了。

2. 英语中引导同位语从句的连接词通常有连词that，whether, 连接代词what，who。连接副词how, when, where等。（注：if, which 不能引导同位语从句。）

3.连词that引导同位语从句

The idea that you can do this work well without thinking is quite wrong.

你认为不动脑筋就能做好这件工作的想法是完全错误的。

◆引导同位语从句的连词that通常不省略，但在非正式文体中也可以省去。

He grabbed his suitcase and gave the impression he was boarding the Tokyo plane. 他拿起了手提箱，给人的印象是他要登上飞往东京的飞机了。

4. 连词whether引导的同位语从句

The question whether we should call in a specialist was answered by the family doctor. 我们是否请专家由家庭医生来定。

★whether 可引导同位语从句，但if不能引导同位语从句。

5. 其它引导词引导的同位语从句

①I have no idea what size shoes she wears.

我不知道她穿几号的鞋。（what作定语）

②The question who will take his place is still not clear. （who作主语）

③We haven't yet settled the question where we are going to spend our summer vacation. 到哪儿去度暑假，这个问题我们还没有决定。

④It’s the question how he did it.

6.同位语从句常见句型：

①have no idea +wh-同位语从句

Sorry, I really have no idea where she lives.

Have you any idea when she is leaving for Beijing?

②have an idea + that引导同位语从句

I have an idea that she won’t leave me whatever happens.

③there is no need// no doubt + that引导同位语从句

There is no need that you worry about his safety, you see, he is a big boy now.

There is no doubt that he is devoted to you.

④there is (great) doubt + 同位语从句

There is great doubt who have stolen the car .

⑤Word came + that引导同位语从句

(为了使句子结构更加平衡，抽象名词作主语而后面接有一个同位语从句时，往往把同位语从句后置。)

Word came that the playground in our school would be replaced by a gym. Information has been put forward that more middle school graduates will be admitted into universities.

The question came up at the meeting whether we had enough money for our research.

7.that引导的同位语从句与定语从句的区别

①定语从句中的that既代替先行词，同时又在从句中作某个成分（主语或宾语），而同位语从句中的that是连词，只起连接主句与从句的作用，不充当句中任何成分。

②定语从句是形容词性的，其功能是修饰先行词，对先行词加以限定，描述定的性质或特征；同位语从句是名词性的，其功能是对名词进行补充说明。

③定语从句中的that有时可省略而同位语从句中的that一般不能省略。

The news that he told me is that Tom would go abroad next year.

他告诉我的消息是汤姆明年将出国。

（第一个that引导的从句是定语从句，that在从句中作宾语）

The news that Tom would go abroad is told by him.

汤姆将出国的消息是他讲的。（同位语从句，that在句中不作任何成分）

8. When, where, why 引导的同位语从句与定语从句的区别

定语从句：引导词与先行词有关，与先行词的意义基本相同，没有疑问意义。同位语从句：引导词与先行词毫无关系，其意义完全与疑问词相同。

相同点：都作成分

9.同位语从句中的虚拟语气

在某些名词(如demand, wish, suggestion, resolution等)后面的同位语从句要用虚拟语气及谓语动词用, “(should)+动词原形”

There was a suggestion that Brown should be dropped from the team.有一项建议是布朗应该离队。

猜一猜，看看课本中的这些句子是哪种名词性从句？

1.Are you afraid that your friend would not understand what you

are going through?

2.That’s what we looked like.

3.It seemed as if the world was at an end.

4.She insisted that she organized the trip properly.

5.I asked her whether she had looked at a map yet.

6.Could you please tell me where the nearest subway is?