英语名词性从句学习要点大汇总
1. 名词性从句的概念和分类
名词性从句即指在复合句相当于名词的从句，根据在句中的作用不同，名词性从句可分为主语从句、宾语从句、表语从句和同位语从句。如：
How this happened is not clear to anyone. 这件事怎样发生的，谁也不清楚。(包含主语从句)
Tomorrow at this time we’ll know who is elected. 明天这时候我们就会知道谁当选了。(包含宾语从句)
The fact is that they are cross with each other. 事实是他们生彼此的气。(包含表语从句)
I’ve come to the conclusion that it was unwise to do that. 我得出结论这样做是不明智的。(包含同位语从句)
2. 名词性从句的词序与时态
(1)词序问题：名词性从句都必须与陈述句语序相同，即“主语＋谓语”。事实上，任何一种从句，其语序都必须与陈述句的语序相同。如：
你是否能告诉我今天下午他何时离开办公室的？
误：Can you tell me when did he leave his office this afternoon?
正：Can you tell me when he left his office this afternoon?
(2)时态问题：若主句的谓语动词是一般现在时时，宾语从句的谓语动词可根据情况使用各种时态；若主句的谓语动词是一般过去时，宾语从句若不是一个客观事实或真理，其谓语动词也必须用某种过去时态。
3. 主语从句复习要点
在复合句中用作主语的从句叫主语从句。主语从句通常由连词that和whether、连接代词或连接副词以及关系代词型what引导。如：
That he is honest and hardworking is true. 他诚实勤奋是真的。
How the prisoner escaped is a complete mystery. 囚犯如何脱逃完全是一个谜。
Whether it will do us harm remains to be seen. 是否对我们有害还要看一看。
What you have to do is to choose a company to invest in. 你需要做的是选一家公司投资。
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。如：
Who he is is not known.=It’s not known who he is. 人们不知他是谁。
Whether they would support us was a problem.=It was a problem whether they would support us. 他们是否会支持我们还是一个问题。
4. 宾语从句复习要点
在复合句中用作宾语的从句叫宾语从句。宾语从句通常由连词that和whether (if)、连接代词或连接副词以及关系代词型what引导。如：
The boy said that he was sorry for what he said. 那男孩说他对他说的话感到懊悔。
The doctor asked what he had been eating. 医生问他吃什么来着?
She asked when she would know the result of the test. 她问什么时候她才能知道考试的结果。
She described how she had narrowly escaped death. 她描绘她怎样九死一生逃过一劫。
She reported what she had seen to the police. 她把见到的情况向警察报告了。
5. 表语从句复习要点
在复合句中用作表语的从句叫表语从句。引导表语从句的词有连词(that, whether)、连接代词、连接副词、关系代词型what以及as if, as though, because等连词引导。如：
The trouble is that I have lost his address. 麻烦的是我把他的地址丢了。
The question is whether the man can be trusted. 问题在于那男人是否可靠。
Now the question is where we can get the raw material. 现在的问题是在哪里能找到原料。
It sounds as if (as though) the situation will get worse. 听起来好像情况会恶化似的。
请注意that’s why…与that’s because…的区别，前者强调结果，后者强调原因。如：
I had a bad cold. That’s why I didn’t come. 我重感冒了，因此我没来。
He is my friend and that’s why I have accepted the task. (并列复合句)他是我的朋友，因此我才接受了这个任务。
That’s because you can’t appreciate music. 这是因为你不能欣赏音乐。
6. 同位语从句复习要点
在复合句中用作同位语的从句叫同位语从句。受同位语从句修饰的先行词通常为fact, news, idea, thought, reply, report, remark等抽象名词，其通常用连词that引导，有时也可用whether以及连接代词和连接副词引导。如：
The news that we are having a holiday tomorrow is not true. 明天放假的消息不实。
There was a suggestion that Brown should be dropped from the team. 有一项建议是布朗应该离队。
The fact that the money has gone does not mean it was stolen. 那笔钱不见了这一事实并不意味着是被偷了。
注意，whether可以引导同位语从句，但if不行。如：
Answer my question whether you are coming. 你回答我的问题：你来不来。(不能用if)
7. 引导名词性从句的what
引导名词性从句的what在从句中作主语、宾语、表语或定语。what有时具有疑问代词的性质，意为“什么”“什么样的”；有时具有关系代词的性质，意为“所……的”，相当于“先行词＋关系代词that”，即相当于“the＋名词＋that”或all that。如：
(1) 相当于疑问代词
Do you know what his sickness is? 你知道他患什么病吗?
Look about and tell me what you see. 向四周望望，告诉我你看到了什么。
(2) 相当于“先行词+关系代词”
What he had hoped at last came true. 他希望的事最后实现了。
He was deeply touched by what she said. 她的话深深触动了他。
We can learn what we did not know. 我们可以学会我们不知道的东西。
8. –ever引导的名词性从句
这些词包括whatever, whoever, whichever等，它们可用于引导主语从句和宾语从句。其中whatever大致相当于anything that或what，但语气比what更强；whoever大致相当于anyone who；whichever大致相当于any that或any…that。如：
I will just say whatever comes into my mind. 我想到什么就说什么。
Whoever breaks the rules will be punished. 谁违反这些规则都将受到处罚。
I’ll give the ticket to whoever wants it. 请想要这票，我就把它给谁。
Whichever team gains the most points wins. 哪个队得分最多，哪个队就赢。
Whichever of us gets home first starts cooking. 我们当中无论哪个先到家，哪个就先开始做饭。
9. “疑问词＋do you think＋从句”类句型
当think, believe, suppose等的疑问式后接疑问词(连接代词和连接副词)引导的宾语从句时，习惯上将疑问词置于句首。如：
What do you think she would feel? 你想她会有什么感觉?
How long do you think you’ll be gone? 你想你会离开多久?
What do you think the result will be? 你认为会产生什么样的结果?
When do you think it can be operated on? 你想什么时候可以给它动手术?
注：有时what do you think…后接的不是一个从句，而是句子的谓语，此时do you think可视为一个插入成分。如：
Which idea do you think is best? 你认为哪个主意最好？
Who do you think will win on Saturday? 你认为星期六谁会赢?