名词性从句
名词性从句就是在句子中充当名词功能的以相关从属连词引导的从句,包括主语从句、宾语从句、表语从句和同位语从句四种.
1．主语从句：以连词 that what whom whose what which whoever whatever whichever where when how why 引导,在句子中充当主语.
例：What she said is not yet known.
How this happened is not clear to anyone.
Whoever comes is welcome.
That she will do well is her exam is certain.（It is certain that she will do well in her exam.）
注：it 为形式主语,
2．宾语从句：以连词 that who whom whose what 等引导,在句子中充当宾语.
例：He told us that he felt ill.
Everybody knows what happened.
I doubt whether he will succeed.
I wonder what he is writing about.
3．表语从句：以 that whether who whom whoever when where when 等引导,在句子中充当表语.
例：The trouble is that I lost his address.
The question is whether they will be able to help us.
That was what she did this morning.
This is why we puts off the sports meeting.
4．同位语从句：同位语从句有自己的先行词,它跟定语从句很相似,先行词包含从句中所含内容,从句不起修饰作用.我们将在学习定语从句时,在加以详细比较,多用在连词what 引导.（不用which,此外还可用whether who where 等也可以引导.在这章中我们着重学习that whether 引导的同位语从句,引导同位语从句的先行词常用的有：fact news idea whether reply promise truth report remark 等.
例：I heard the news that the Chinese football team defeated the Japanese team
last night.
I have no idea whether he will come or not.
They were all much worried over the fact that you were sick.
关于名词性从句的学习主要是我们应在学习中加以练习,在练习中反复学习,在多次重复学习和练习中加以掌握.