高中名词性从句知识点汇总

名词性从句知识点汇总

在句中起名词作用从句叫做名词性从句。名词性从句的功能相当于名词短语，在复合句中能担当主语、

宾语、表语、同位语等。根据它在句中不同的语法功能，名词性从句分为主语从句、宾语从句、表语从句和同位语从句。名词性从句的引导词可分为3类：

从属连词：只起连接作用，不充当从句中的任何成分。包括：that,whether,if,as if,as though

连接代词：既起连接作用，本身又作从句的主语、宾语、表语或定语。包括：

who,whom,whose,which,what,whoever,whatever,whichever,whomever.

连接副词：既起连接作用，本身又作从句的状语。包括:whe n, where,how,why

s

一、主语从句

可以直接放在句首，也可以用形式主语it代替，将主语从句放在句末。

1. that引导的主语从句

that引导主语从句时只起连接作用，没有实际意义，也不在从句中作任何成分，但不能省略。

That the earth moves around the sun is known to all.

2. whether,if引导主语从句

whether :引导主语从句既可以放在句首，也可以放在句末，只起连接作用，不作成分if :引导主语从句只能放在句末，前面用it作形式主语。

whether you can succeed or not depe nds on how hard you work at it.

It is unknown whether/if he has agreed to my pla n.

3. 连接代词或连接副词引导主语从句

连接代词在从句中作主语、宾语、表语或定语。

连接副词在从句中作状语。

What they n eed are a car and some water.

Why they sudde nly disappo in ted still rema ins a mystery.

4.it作形式主语的主语从句

1) lt+be+adj./n./ 过去分词+that 从句

It has bee n predicted that mobile phones might soon replace our wallets.

2) It+seem(ed)/happen(ed)等不及物动词及短语+that从句

It seemed that each of them was satisfied with the results.

3) It doesn ' t matter+how/whether

It does n ' t matter whether he will jo in the club or not.

4) that引导主语从句出现在疑问句中，用it作形式主语，把主语从句后置

Is it likely that your friend will come this eve ning?

5) 当主语从句出现在感叹句中时，要以it作形式主语，而把主语从句后置

What a pity it is that you missed a won derful football match!

二、宾语从句

1. 动词接宾语从句

1) 宾语从句紧跟在及物动词后：She won dered who had sent the flowers.

2) 常用it 作形式宾语：He had made it clear that the meeting not be postponed.( 有宾补的情况下)

2. 介词接宾语从句

1) 介词后面可以跟whether和wh-类连接词引导的宾语从句

He only cares about whether the eyewit ness has give n true in formati on.

2) 介词except,but,besides,in后有时可以直接接that引导的宾语从句。除这些之外，that引导的从句一般不

直接作介词的宾语。其他介词后接that从句作宾语时，必须用it作形式宾语。

I didn ' t tell him anything except that I needed the money.

You may depe nd on it that I should always help you.

3. 系表结构接宾语从句

Sure,certa in, glad,pleased,happy,afraid,surprised,satisfied,sorry 等表示情感的形容词与be 其后

起构成系表结构, 的从句也可视为宾语从句。

I ' m con fide nt that you will get the job.

I ' m glad that you can come here on time.

4. 只用whether不用if的情况

1）在介词后弓丨导宾语从句：Everyth ing depe nd on whether you agree with us.

2）宾语从句置于句首：Whether they like the presents, we don ' t know.

3）与or not 连用时：I want to know whether or not the train goes to King street.

4）与不定式连用时:I can ' t decided whether to stay.

5）在动词discuss, wonder, doubt, leave, put 后弓丨导宾语从句:

We discussed whether we should close the shop.

5. 宾语从句中不能省略that的情况

1）宾语从句前有插入语：We hope, on the con trary,that he will stay at home with us.

2）宾语从句紧跟在间接宾语之后时，或主语状语置于宾语从句之前时

He told me that he was leaving for Australia.

I realized at once that I hadn ' t turn off the gas.

3）当it作形式宾语，后接that引导的宾语从句时

I don ' t think it polite that they left without saying thanks to us.

4）that引导的从句位于句首

That our team will win,I believe.

5）宾语从句在except,but,besides,in等介词之后

He also likes play ing the pia no besides that he is good at play ing basketball.

6）that引导的从句与其他引导词引导的从句作并列宾语

I know where we will go and that we ' ll be back in three days.

7）多个并列的that引导的宾语从句，只有第一个that可以省略8）宾语从句的主语是非谓语动词或从句

The doctor said that tak ing exercise was the best way of los ing weight.

9）宾语从句的主语是this,that或有this,that修饰时

She told me that that was why she was late.

10）宾语从句为主从复合句，从句位于宾语从句的前部

I promised that if anyone came to set me free,I would make him king over the earth.

三、表语从句