在句子中起名词作用的句子叫名词性从句。名词从句的功能相当于名词词组, 它在复合句中能担任主语、宾语、介词宾语、表语、同位语等，因此根据它在句中不同的语法功能，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。

引导名词性从句的连接词可分为三类：

连接词：  that, whether, if （不充当从句的任何成分）

              这三个词的区别要清楚

连接代词：who, what, which, whose, whoever, whichever, whomever ，whatever 

连接副词 where, when, why, how, wherever, whenever, however

主语从句

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。

主语从句example

1． That price will go up is certain.

2．   How you travel means the difference between success and failure.

3． Whether we go by train or by boat makes no difference.

4． Who will write the poem has not been decided yet.

5． What surprised us is that he lost in the game.

6． What he left us was a large sum of money.

7． When he will be back depends on the weather.

8． Where we live doesn’t matter.

9． How the pyramids were built was still a mystery.

10. Watever he did is right.

11. Whoever comes will be welcome.

12. Whichever you want is yours.

主语从句notes

1．that引导的主语从句中，that不可被省略

That price will go up is certain.

2．demand, insist, order, request, require, suggest引导主语从句时，其后的主句要用虚拟语气,eg:

What he suggests is that we ( should) arrive as early as possible.

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。如：1) What you said yesterday is right.

　    2) That she is still alive is a wonder.

宾语从句

宾语从句就是在复合句中作宾语的名词性从句，通常放在主句谓语动词（及物动词）或介词之后。

宾语从句sturcture

1．动词+ 宾语从句

We hope that you will enjoy your stay here.

Tell me why you don’t like school.

2．介词+ 宾语从句

Don’t ask about what the meeting is for.

Our success depends on / upon how well we can cooperate with one another.

3．形容词+ 宾语从句

We are certain that this is true.

I’m afraid that I can’t help you.

He wasn’t sure whether he ought to laugh or cry.

4．补充：at引导的从句常跟在下列形容词后作宾语：

　Anxious, aware, certain, confident, convinced, determined, glad, proud, surprised, worried, sorry, thankful, ashamed, disappointed, annoyed, pleased, hurt, satisfied, content 等。也可以将此类词后的that 从句的看作原因状语从句。

5．动词+ it +从句 （ it没有任何意义 ）

I heard it that he had gone abroad.

I hate it when people speak with their mouth full.

I appreciated it very much that he had done me a favor.

6. 主语 + 谓语 + 形式宾语it + 宾补 +宾语从句

I feel it a terrible thing that I have to get up so early.

I took it for granted that you would stay with us.

They kept it quiet that he was dead.

宾语从句notes

1．that引导的宾语从句中，that可被省略

2．demand, insist, order, request, require, suggest在主句中，2其后的宾语从句要用虚拟语气

I suggest that all the students (should ) be present at 5 o’clock.

3． think, consider, suppose, believe, expect, fancy, guess, imagine等其后的宾语从句若含有否定意义，要将否定词移到主句谓语上，从句谓语用肯定形式,eg: I don’t think he can do better than me.

主语从句及宾语从句小结

1.主语从句和宾语从句中用陈述语序

What she is afraid of is their taking her to Paris.

( What is she afraid of …  Wrong )

宾语从句中有例外：

He asked me what was the matter with me.

He asked me what was wrong with me.

2.主语从句后谓语动词用第三人称单数

That they haven’t phoned is strange.

3. 从句中用了what, when等连接词就不要再用that

That what I want to know is his address.  (Wrong )

What I want to know is his address.

如果是插入语，则去掉插入语不影响句子的理解

Who do you think he is?

What do you suppose he wants?

All of them agree to accept whoever they thought was the best at playing football.

表语从句

表语从句是在复合句中作表语的名词性从句，放在系动词之后，一般结构是“主语＋连系动词＋表语从句”。可以接表语从句的连系动词有be, look, remain, seem等。另外，常用的还有the reason is that… 和It is because 等结构。

表语从句example:

1. The reason was that he didn’t work hard.

2. New York is no longer what it was ten years ago.

3. That’s what makes him an excellent conductor.

4. That is why he turned me down.

5. The book is where you left it.

6. This is where you are wrong.

7. The question remains whether we can win the majority of the people.

表语从句小结：