高中名词性从句语法

起名词作用 的从句叫作名词性从句 引导名词性从句的连接词有三种

1连接词that.它在名从中只起连接作用，并且本身没有意思。在名从中不能充当句子成分

2连接词if,whether 也是只起连接作用，但有是否的意思，也不能充当句子成分。

3.连接代词what，which，who等和连接副词where,when,how等 代词在名从中作主语或宾语，表语，定语。连接副词在宾从中作状语个别除状语外可做表语[when,how]

在做题时 首先分析从句的句子结构。如句子完整，意思完整就用that。

句子完整意思不完整 则考虑用if或用连接副词

句子不完整 缺主语 或者缺宾语就一定要用连接代词。

另外注意that 在定语从句中叫作关系代词 在定从中起代词作用。不要搞混了。

名词性从句 可充当主语从句 宾语从句 表语从句 和同位语从句 先分别举例如下

主语从句

what you did made me angry.

what you said made me happy.

it is true that he will come tomorrow.

it is said that a building will be built.

why he was late was that he he didn't catch the bus.

whether he will come is unknown.

表语从句

our trouble is where we can get money.

my difficulty is how I can finish the work.

Beijing isn't what it used to be.

the book is what you are looking for.

宾语从句

I don't know whom she likes.

I don't know who will come.

I don't know which book is yours.

同位语从句

the news that he has died is true.

I have no idea where he has gone.

the fact that he works hard is well known.

he made a promise that he would buy a car for me.