英语语法的主语从句【4篇】

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英语语法的主语从句 篇1

一、定义 ：

在复合句中起主语作用的从句叫做主语从句。

二、位置：

一般与陈述句基本结构中的主语相同。但多数情况下用it做形式主语，而把主语从句放在主句之后，避免头重脚轻。

三、主语从句的种类

(1) 由连词that引导的主语从句。

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) 用连接代词或连接副词if, whether 引导的主语从句。

例如： Which of them escaped from the prison is still a mystery.

他们哪一个是从监狱里逃跑的，仍然是个谜。

When they will come hasn’t been made pubic.

他们什么时候来还不知道。

Whether she is coming or not doesn’t matter too much.

她来不来都无关紧要。

(3) 用关系代词引导的主语从句。

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。

主语从句可以直接放在主语位置上，也可以用it作形式主语，

而将从句放在句末(尤其是当谓语较短时)。

例如：That light travels in straight lines is knownto 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。

如果带主语从句的句子是疑问式，则必须用it作形式主语的结构。

例如：Has it been settled who will be sent to carry outthe task ?

谁将被派去执行这项任务决定了吗 ?

四、主语从句常用结构

(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 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 + 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.

例如：It is obvious that conductors and insulators areboth 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; madeclear; 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 twostars. 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 mad-§ e clear when the new road is to be opened to traffic.

还没弄清楚这条路将开始通车。

(4) It + 不及物动词 + 从句

It seems that … 好像是……

It happened that… 碰巧……

It follows that … 由此可见……

It has turned out that … 结果是……

类似的不及物动词还有：seem, appear, occur, follow, happen, turnout, etc.

例如：It turned out that nobody remembered the address.

结果是无人记得那个地址。

It now appears that they are in urgent need of help.

看起来他们急需帮助。

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 wherehe 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。

It +某些固定结构+ 主语从句。

例如：It doesn’t make too much difference (It doesn’t make any difference / It doesn’t alter the situation)，whether it rains or not . 下不下雨都没有多大关系。

It does not make any difference whether it rains or not .

下不下雨没什么分别。

It does not make the least difference to me what you do.

对我来说你做什么都无关紧要。

Is it of much consequence to you that Mr. Wang has failed to do it ? 王先生没有做成这件事对你有什么重要影响吗？

英语语法的主语从句 篇2

即在复合句中充当主语成分的句子，例如"That he finished writing the composition in such a short time surprised us all"，他在很短的时间内写完作文让我们都很惊讶，此复合句主要描述的是某事让我们惊讶，某事就是该复合句的主语，因此“That he finished writing the composition in such a short time”便是该复合句的主语从句。

引导主语从句的连词主要有：

从属连词：that whether

连接代词：who whoever whom whose what whatever which whichever

连接副词：when where how why

定义：在复合句中充当主语成分的句子叫做主语从句。

主语从句的时态不受主句时态的影响和限制

（1）That he finished writing the composition in such a short time surprised us all.

（2）Whether we will go for an outing tomorrow remains unknown.

（3）Who will be our monitor hasn't been decided yet.

（4）Whom we must study for is a question of great importance.

（5）What caused the accident remains unknown.

（6）Whatever you did is right.

（7）Whom the watch belongs to is unknown.

（8）What we need is time.

（9）What we need are good doctors.

名词性从句的时态规则：

1）、主句谓语动词是现在或将来时，从句谓语动词可以用任何需要的时态。

I wonder what he is doing now.

Do you know when and where he was born?

I'll write to tell him where I 'll meet him.

2）、主句谓语动词是过去时，从句谓语动词一般需用过去时。

（1）从句与主句的谓语动作同时发生，从句用一般过去时或过去进行时。

I thought that he studied hard.

He told me his son was watching TV.

（2）从句谓语动作在主句谓语动作之后，从句用过去将来时。

He said he would spend his holidays in Qingdao.

（3）从句谓语动作在主句谓语动作之前，从句用过去完成时。

They told me they had waited for me half an hour.

（4）从句如果有表示过去某一具体时间的状语，仍用过去时。

She told me her brother died in 1945.

3)客观的条件，从句时态不受丝毫影响。

（1）从句说明的是不受时间限制的事实或真理（客观真理）。

The teacher told us that the earth turns from west to east.

He said Asia is the largest continent.

It was true that water freezes at thirty-two degrees Fahrenheit.

（2）当从句表示的是反复出现的时态不变。

She told me that she gets up at six o'clock every morning.

He asked me when the train usually starts.

（3）当从句是用来表达解释科技内容时时态不变。

（4）当从句的谓语动作仍在继续时，或者表示现在仍在的状态时，时态不变。

He said that the workers in that factory are trying to fulfill the task in time.

She told me the other day that she is only 10.

（5）当从句的动作状态还未发生，要用一般式表示。强调与现在的联系。

He said he will wait for me this evening.

小结：

（1）引导主语从句连词有that,whether,who,what,whatever等

（2）连词位于句首不能省略

（3）主语从句大多数情况下视为第三人称单数，但也有例外；

注意：当what引导的名词性分句作主语时，主谓一致问题极为复杂。著名学者周海中教授在论文《关于what-分句作主语的主谓一致问题》中就这一问题做了深入研究，并给出了10种的主谓一致关系。这些一致关系值得英语学习者和使用者特别注意。

定语从句

一个简单句跟在一名词或代词后（先行词）进行修饰限定，就叫做定语从句。在主句中充当定语成分。被修饰的词叫先行词。定语从句不同于单词作定语的情况，它通常只能放在被修饰的词（即先行词）之后。

定语 从句由关系词（关系代词、关系副词）引导，关系代词、关系副词位于定语从句句首。

关系代词引导的定语从句

关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。关系代词在定语 从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。

1）who, whom,that

这些词代替的先行词是人的名词或代词，在从句中所起作用如下：

Is he the man who/that wants to see you?

他就是想见你的人吗？（who/that在从句中作主语） He is the man whom/ that I saw yesterday.

他就是我昨天见的那个人。（whom/that在从句中作宾语）

2) Whose 用来指人或物，(只用作定语， 若指物，它还可以同of which互换）, 例如：

They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。

Please pass me the book whose (of which) cover is green. 请递给我那本绿皮的书。

3）which, that

它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等，例如：

A prosperitywhich / thathad never been seen before appears in the countryside. 农村出现了前所未 有的繁荣。（which / that在句中作主语）

The packagewhich / thatyou are carrying is about to come unwrapped. 你拿的包快散了。(which / that 在句中作宾语）

关系副词引导的定语从句

关系副词可代替的先行词是时间、地点或理由的名词，在从句中作状语。

1）when, where, why

关系副词when, where, why的含义相当于"介词+ which"结构，因此常常和"介词+ which"结构交替使用，例 如：

There are occasions when (on which) one must yield. 任何人都有不得不屈服的时候。

Beijing is the place where (in which) I was born.北京是我的出生地。

Is this the reason why (for which) he refused our offer? 这就是他拒绝我们帮助他的理由吗？

2）that代替关系副词

that可以用于表示时间、地点、方式、理由的名词后取代when, where, why和"介词+ which"引导的定语从 句，在非正式文体中that常被省略（正式文体中不可省略），例如：

His father died the year (that / when / in which) he was born. 他父亲在他出生那年逝世了。

He is unlikely to find the place (that / where / in which) he lived forty years ago. 他不大可能找到他四十 年前居住过的地方。

判断关系代词与关系副词

方法一： 用关系代词，还是关系副词完全取决于从句中的谓语动词。及物动词后面无宾语，就必须要 求用关系代词。例如：

（错） This is the mountain village where I visited last year.

（错） I will never forget the days when I spent in the countryside.

（对） This is the mountain village (which) I visited last year.

（对） I'll never forget the days (which) I spent in the countryside.

习惯上总把表地点或时间的名词与关系副词 where, when联系在一起。此两题错在关系词的误用上。

方法二： 准确判断先行词在定语从句中的成分(主、谓、宾、定、状)，也能正确选择出关系代词/关系 副词。先行词在从句中作主、定、宾语时，应选择关系代词；先行词在从句中作状语时，应选 择关系副词。

例如：（对）Is this the museum which you visited a few days ago?

（对）Is this the museum where the exhibition was held?

从句结构

定语从句公式

定语从句=先行词+关系词+从句

先行词

指被定语从句修饰的名词、代词或句子。

一般先行词出现在定语从句的前面。

关系词

关系词常有3个作用：

①连接作用，连接主句和定语从句。

②指代先行词。

③在定语从句中担当成分。

注：关系代词有主语、宾语、定语之分。一般who做主语或其宾格形式的'whom做宾语(whom作宾语时可省略），whose作为定语（whose不可省略）。关系代词在从句中作主语，宾语，定语等，关系副词在从句中作地点状语（where），时间状语（when），原因状语（why）。[1]

定语用来限定、修饰名词或代词，是对名词或代词起修饰、限定作用的词、短语（动词不定式短语、动名词表示的）汉语中常用“……的”表示。主要由形容词担任，此外，名词、代词、数词、分词、副词、不定式以及介词短语也可以来担任，也可以由一个句子来担任。单词作定语时通常放在它所修饰的词之前，作前置定语。短语、从句作定语时则放在所修饰的词之后，作后置定语。

被定语从句修饰的名词、代词称为先行词。如“the girl”，“the book”

如：She is the girl who likes singing. 她就是那个喜欢唱歌的女孩。

这就是一个定语从句。

英语语法的主语从句 篇3

1.以what等连接代词引导的主语从句

What you need is more practice. 你需要的是更多的练习。

Whoever wants it may have it. 谁要都可以给他。

同类的连接代词还有：What, who, whom, whose, which, whatever, whoever, whichever

2.以that, whether从属连词引导的主语从句

It was strange that he had made a mistake. 真奇怪，他竟然错了。

That we need more equipment is quite obvious. 我们需要更多的设备，这是很明显的。

Whether he will join us won't make too much difference.

他是否加入我们，没有太大的差别。

3.主语从句的引导词that什么时候可以省略

当主语从句不太长时，引导词“that”可以省略

It's clear (that) he has done his best. 很明显他已经尽力而为了。

It's a wonder (that) he didn't fail. 真奇怪，他没有失败。

4.以when等连接副词引导的主语从句

When they will come hasn't been made public. 他们什么时候来还没有公布。

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

Why he did it will remain a puzzle for ever. 为什么他做那件事将永远是个谜团。

5.虚拟语气：主语从句

形容词为necessary, important, impossible, strange, natural, essential时，在“It + be + 形容词或过去分词 + 主语从句”中，主语从句要虚拟。

It is necessary that the problem (should) be discussed at once.

立刻讨论这个问题很有必要。

It is strange that he (should) have so many friends. 太奇怪了，他有那么多的朋友。

6.主语从句与强调句的区别

注意事项：

1). 在主语从句中，把It was … that去掉之后，就已经完全不像一个句子了。

2). 在强调句中，把It was … that去掉之后，还基本上像个句子。

3). 主语从句有以下的引导词：what, who, whom, whose, which, whatever, whoever, whichever

4). 强调句的引导词只有：that, who。

主语从句：

It was strange that he had made a mistake. 如果把，It was … that 去掉以后，剩下strange he had made a mistake.就不算是句子了。

It is immaterial where or when he goes. 他去何处或者何时去是无关紧要的。

It is said that…, 和It is reported that…这样的结构，后面接的是主语从句：

It is said that he’s got married. 听说他已经结婚了。

强调句：

It was she that had been wrong. 错的是她。（强调主语）如果把，It was … that 去掉以后，剩下she had been wrong.还勉强算的上是一个句子。

It was this novel that they talked about last night. 他们昨晚谈论的是这部小说。（强调宾语）

It was in London that I first saw her. 我是在伦敦第一次见到她的。（强调地点状语）

英语语法的主语从句 篇4

主语从句是在复合句中充当主语的从句，通常放在主句谓语动词之前或由形式主语it代替，而本身放在句子末尾。

1. It 作形式主语和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，主语从句的连接词没有变化。而it引导的强调句则是对句子某一部分进行强调，无论强调的是什么成分，都可用连词that。被强调部分指人是也可用who/whom。例如： It is a pity that you didn’t go to see the film. It doesn’t interest me whether you succeed or not. It is in the morning that the murder took place. It is John that broke the window.

2. 用it 作形式主语的结构

(1) It is ＋名词＋从句 It is a fact that … 事实是… It is an honor that …非常荣幸 It is common knowledge that …是常识

(2) it is ＋形容词＋从句 It is natural that… 很自然… It is strange that… 奇怪的是…

(3) it is ＋不及物动词＋从句 It seems that… 似乎… It happened that… 碰巧…

(4) it ＋过去分词＋从句 It is reported that… 据报道… It has been proved that… 已证实…

3. 主语从句不可位于句首的五种情况

(1) if 引导的主语从句不可居于复合句句首。

(2) It is said , (reported) …结构中的主语从句不可提前。例如： It is said that President Jingo will visit our school next week. (right) That President Jiang will visit our school next week is said. (wrong)

(3) It happens…, It occurs… 结构中的主语从句不可提前。例如： It occurred to him that he failed in the examination. (right) That he failed in the examination occurred to him. (wrong)

(4) It doesn’t matter how/whether …结构中的主语从句不可提前。例如： It doesn’t matter whether he is wrong or not. (right) Whether he is wrong or not doesn’t matter. (wrong)

(5) 含主语从句的复合句是疑问句时，主语从句不可提前。例如： Is it likely that it will rain in the evening? (right) Is that will rain in the evening likely? (wrong)

4. 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.