初探名词性从句

名词性从句是一种具有名词功能的非独立从句。

名词性从句可以由that ，whether/if ，特殊疑问词引导；还有以what 和wh-ever等连接代词引导的名词性关系从句。

1 主语从句

一个从句在整个句子中做主语，那这个从句就叫主语从句。

1.1 如果从句成分完整，不缺什么成分就由that 引导，that 只起连接作用，没有实际意义。

（1）It is adj.( obvious/ true/ certain/ likely……) +that 从句.

It is certain that she will do well in her exam.

It is likely that he told her everything.

(2) It is + 名词词组( no wonder / an honour / a pity/no surprise)+that从句.

It is no surprise that our team has won the game.

(3) It is + 过去分词(said / reported /thought / expected / decided / announced / arranged……) + that 从句

It is said that Mr. Green has arrived in Beijing.

It is decided that the meeting has been put off till next Monday.

注意:口语和非正式文体中, that 常可省略, 尤其是非常短的句子中, that 总是不必要的, 但that 从句位于句首时, 连词that 绝对不能省.

It’s a pity ( that ) you’re leaving.

That we are invited to a concert this evening is good news to us.

1.2 用whether /if (是否) 引导的主语从句.

当主语从句放于句首时, 主语从句只能用whether , 不用if引导;

当it 做形式主语时, 主语从句用whether / if 引导均可.

( 是否) the meeting will be given is still a problem.

=It is still a problem________( 是否) the meeting will be given.

1.3 用特殊疑问词引导主语从句时, 主语从句缺什么意思用什么引导词, 如when，where，why ，what ，how，which，who。语序要用正常语序,即特殊疑问词+主语+谓语+其他。也可用it 作形式主语。

It makes no difference________(什么地方) we shall have the meeting.

It has not been decided yet________( 谁) will attend the meeting.

2 宾语从句

用于及物动词后和介词后充当宾语的句子叫宾语从句。

2.1 that 引导的宾语从句

（1）that 引导的宾语从句用在及物动词后，其中that只起连接作用，不充当成分，可以省略。

Do you know （that ）he has joined the army？

I’m sure （that）he will pass the exam。

（2）但是及物动词后若有两个that 引导的宾语从句，则第一个that 可省，第二个that 不能省。

He makes me understand ( that ) we need friends and that we should give him a hand.

(3) 在可以接复合宾语的动词之后，如think, find, make, consider 等，可以用it 作形式宾语, that不能省略。

He has made it clear that he will not give in.

We think it necessary that he should improve his pronunciation.

(4) that 从句一般不能充当介词宾语, 偶尔可作except , in 的宾语，that不能省略。

He is a good student except that he is a little bit careless.

He differed from his classmates in that he devoted his spare time to reading.

(5) 其他介词后面要用that 从句作宾语时, 必须用it 作形式宾语，that不能省略。

You may depend /count/ rely on it that I shall always help you. (相信)

You can count/depend/rely on it that he is very smart. (相信)

Please see to it that you bring enough money when you go out. (务必)

2.2 whether /if 引导的宾语从句

(1) 在一般的及物动词后, 用whether /if 均可, 但discuss 后必须用whether 引导, 不能用if 引导宾语从句.

I doubt________ ( 是否) he will come here.

Let’s discuss________ (是否) the meeting should be put off .

(2) whether 所引导的从句不能用否定式；…whether /if…or not 或…. whether /if or not ….形式存在；if or not 不存在；跟不定式连用必须用whether ，不用if。

I don’t care whether he doesn’t come. (×)

I don’t care whether /if he comes or not . (∨)

I don’t care whether or not he comes . (∨)

I don’t care if or not he comes . (×)

I don’t care whether to go there. (∨)

(3) 在介词后表示是否只用whether 不用if .

It depends on (取决于)________(是否)you can do the work well.

This decision will have an effect on ________ ( 是否)or not he will succeed.

2.3 特殊疑问词引导的宾语从句, 宾语从句想表达什么意思就用相应意思的引导词, 如when，where，why ，what ，how，which，who。语序要用正常语序,即特殊疑问词+主语+谓语+其他.

(1) 特殊疑问词用在及物动词后引导宾语从句.

I can’t imagine________(如何) he did it.

They couldn’t understand________( 为什么) I refused it.

(2)特殊疑问词用在介词后引导宾语从句

It all depends (on) ________ ( 如何) we solve the problem.

We are worrying about________ (什么) we should do next .

3 表语从句

英语中有一种基本结构是主语+系动词+表语, 若系动词后面的表语是由一个句子来充当的,我们就称其为表语从句. 表语从句想表达什么意思就用相应意思的引导词, 如,whether (是否), when，where，why (为什么) ，because(因为), what ，how，which，who，as if /as though。若不缺成分, 则用that 引导,不可以省略. 语序要用正常语序,即特殊疑问词+主语+谓语+其他.

1. My decision is________ all of us are to start at 6 o’clock tomorrow morning.

2. The problem is ________ ( 是否) the meeting will be given .

3. The problem is________(哪里) we should stay.

4. This is________ we disagree. ( 分歧所在)

5. This is________our problem lies. (问题所在)

6. The ground is wet. That is________( 因为) it rained last night.

7. It rained last night. That is________( 为什么) the ground is wet.

8. It looked as if it was going to rain.

4 同位语从句

如果一个句子与主句中的某个名词是同位语关系( 句子对名词起解释说明的作用), 那我们就称这个句子为同位语从句. 常见的此类名词多为抽象名词: fact, hope , desire, feeling , thought , suggestion, idea , news , word( 消息), problems, possibility 等. 从句对名词起补充说明的作用。常用连词that 来引导同位语从句，其中that 只起引导作用, 不充当成分, 亦不能省略. 其他情况下缺什么意思用什么引导词, 如when，where，why ，what ，how，which，who。语序要用正常语序,即特殊疑问词+主语+谓语+其他。

1. I have no idea________ ( 是否) the meeting will be given.

2. My question________ ( 如何) I shall get in touch with him has not been answered.

3. There is a feeling in me that we’ll never know what a UFO is .

4. I still remember the story that we got lost on a rainy night.

5. Is there any possibility that you could pick me up at the airport?

6. Word came that we won the first prize.

5 名词性关系从句

名词性关系从句实际上是先行词与在其后的定语从句的结合. what 是最常用来引导名词性关系从句的关系代词, 此时what= the thing(s) which/that, 有时what 可以用作前置定语, 如what help, what funny stories 等. 此外, whoever = anyone who ; whichever = anyone /anything that ( whichever 也可指人) ; whatever = anything that ( whichever 和whatever 也可作定语). 有时where = the place where 和when = the time when 也可以用来引导名词性关系从句.

5.1 主语从句。

What they need is a good textbook.

Whichever he likes will be given to him.

Whichever book he bought would be paid for.

Whoever did this jobmust be rewarded.

5.2 宾语从句。

She will give whoever (=anyone who) needs helpa warm support.

She walks up to where (=the place where ) he stood.

I can judge by what (=the things that ) I know of him.

You can write about whatever topic (=any topic that ) you prefer.

5.3 表语从句。

China is no longer what it used to be.

The boy is no longer what he used to be.

Tomorrow is when it would be most convenient.

5.4 同位语从句。

I gave the girl a big doll, exactly what she longed to have.

5.5 名词性关系从句还可以作宾语补足语。

We’ll make him whatever he is fit for.

I will call the baby whatever name you like.

He has made the company what it is today.