【原】主语从句用法分析

一、主语从句的连词分三类

1、从属连词 that、whether 和 if 引导的主语从句

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.      

你不太可能赢得奖牌。

        

That she survived the accident is a miracle.  

她在事故中幸存下来真是奇迹。

whether 引导的主语从句:  if/whether 有含义(是否)/在句中不做成分/不可以省。注意：引导主语从句时，不能把 if 放在开头，只能用 whether，例如：

Whether we will hold a party in the open air tomorrow depends on the weather.  

明天我们是否举行露天聚会要看天气而定。

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

她来不来无关紧要。

It is unknown if/whether he will come.   

他是否来还不知道。

2、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，在从句担当一定成分，例如：

who:

Who laughs last lauhs best.

谁笑到最后谁笑得最好。

Who is able to be egotistical needs to be strong too.

有本事任性的人，也要有本事坚强。

whose:

Whose the money is doesn’t concern me. 

这是谁的钱与我无关。

Whose watch was lost is unknown.

谁的表丢了还不知道。

whom:

Whom you talked to just now will be confirmed later. 

你刚才跟谁说话了，之后会证实的。

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

“我们为谁而学习”是个很重要的问题。

which:

Which design is the best must be tried in practice.

哪种设计是最好的，必须在实践中加以尝试。

Which style is more acceptable hasn't been decided.

哪种款式更容易接受还没有决定。

what:

What upset me most was his rudeness.

最让我不安的是他的粗鲁。

What we gave them was some homemade cake.

我们给他们的是一些自制的蛋糕。

whoever:

Whoever is elected will serve a four-year term.

无论谁当选，任期四年。

Whoever says that is a liar.

说那话的人都是骗子。

whomever:

Whomever you elect will serve a four-year term.

无论你选谁，任期四年。

Whomever you invite is welcome. 

你邀请的任何人都将受欢迎。

whichever:

Whichever book you read will tell you the same.

无论你读哪本书，都会告诉你同样的道理。

Whichever you want is yours.

你要哪一个，哪一个就是你的。

whatever:

Whatever we do is to serve the people.

我们所做的一切就是为人民服务。

Whatever happened between us is none of your business.

我们之间发生的一切都不关你的事

注：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，例如：

Whoever breaks the law should be punished. ---->主语从句

任何违法的人都应该受到惩罚。

Whoever breaks the law, he should be punished. ---->让步状语从句

不管谁犯法，他都应该受到惩罚。

3、用连接副词 when, where, why, how 引导的名词性从句，在句中有含义，在句中作状语。例如：

when:

When she'll be back depends much on the weather.

她何时回来在很大程度上取决于天气。

When he was born is unknown. 

他生于何时还不知道。

where:

Where we should leave it is a problem.

我们应该把它放在哪里是个问题。

Where we stay doesn't matter.

我们住在哪没有什么关系。

why:

Why Tony did this remained a mystery. 

为什么托尼做这件事仍然是个谜。

how:

How the accident happened is not clear to anyone.

这场事故是怎么发生的，谁都不清楚。

二、it 作形式主语的主语从句  

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。这分四种情况： 

1、对于以连词that引导的主语从句，通常用形式主语 it 替代主语从句：

 

A、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对我来说是个谜。

It is common knowledge that the whale is not a fish. 

众所周知，鲸鱼不是鱼。

It is no surprise that Bob should have won the game.  

鲍勃本该赢得这场比赛，这并不奇怪。

B、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、unusual、certain、evident、worth-while、surprising、interesting、astonishing 等，例如：

It is doubtful whether she will be able to come. 

她能否来是个疑问。

It is essential that he should be here by the weekend. 

他必须在周末前到这里。

It seems obvious that we can not go on like this. 

显然我们不能这样下去。

It is necessary that you （should）master the computer.   

你有必要掌握计算机。

需要注意的是这类主语从句中，谓语动词很多为“（should）＋动词原形”，即要用虚拟语气。 

C、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 等，例如：

It is used to be thought that a new star must be due to a collision between two stars.

过去人们认为一颗新星一定是由于两颗恒星之间的碰撞造成的。

It has not been made clear when the new road is to be opened to traffic.

这条新路什么时候通车还没有说清楚。

 

D、It seems不及物动词（happened / appears / doesn’t’ matter / makes no difference / occurred ...）that ...主语从句不可提前，例如：

It makes no difference whether he will attend the meeting or not.  

他是否参加会议无关紧要。

  

It does not matter if I missed my train.  

我是否误了火车无关紧要。

It happened that I saw him yesterday.  

我昨天碰巧见到他。

 

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。 

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，例如：

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，例如：

 

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？ 

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 was a pity. ---->that不可省

很遗憾你没去听报告。

It was a pity (that) you didn’t go to the talk. ---->that可省

很遗憾你没去听报告。