概述

一.定义: 在句中的作用相当于一个名词的从句叫做名词性从句
二.分类: 名词性从句包括四类, 分别是: 主语从句, 宾语从句, 表语从句,同位语从句
三.引导词: 名词从句的引导词包括连词that / if / whether, 连接代词who / whom/ whose / what / which, 连接副词when / where / how / why, 另外还有:whatever, whichever, whoever等

主语从句

一.定义: 在句中充当主语的从句就是主语从句
二.示例:

a. That he looked at me in that strange way puzzled me.

b. Whether we can control the floods is still uncertain.

c. What he wanted to see was an end to all the armies of the world.

d. When the broadcast station will be ready is unknown.

e. Who made the long distance call to him is not important.

f. Whether we’ll go depends on the weather.

三.应注意的问题:

1.以that引导主语从句时, 常用it作形式主语, 而把真正主语后移,如在以下句型中就是如此: It is + adj / n + that...; It is said / reported /hoped that...

a. It is certain that fuels like coal and oil cause a lot of pollution.
b. It was said that only three people in the world could understand it at that time.

2.whether引导主语从句时, 常置于句首 (此时whether不能用if代替),
也有后移的用法 (此时whether可以用if代替)

a. Whether they will come is not yet known.

b. It is not yet known whether they will go there.