英语语法：什么是表语从句

Answer 1

顺手采纳答案
表语从句（Predicative Clause）就是用一个句子作为表语。说明主语是什么或者怎么样，由名词、形容词或相当于名词或形容词的词或短语充当表语
一、表语从句的定义：
表语从句放在连系动词之后,充当复合句中的表语.
二、表语从句的构成：
关联词+简单句
三、引导表语从句的关联词的种类：
1.可接表语从句的连系动词有be,look,seem,sound,appear等.
China is no longer what she used to be.
今日的中国不再是过去的中国了.
The question remains whether they will be able to help us.
问题还是他们能否帮我们.
At that time,it seemed as if I couldn't think of the right word.
当时,我似乎怎么也想不出一个恰当的字眼来.
2.从属连词whether,as,as if / though引导的表语从句.
He looked just as he had looked ten years before.
他看起来还与十年前一样.
It sounds as if someone is knocking at the door.
听起来好像有人在敲门.
3.because,why引导的表语从句.
That's because he didn't understand me.
那是因为他没有理解我.（That's because…强调原因）
That's why he got angry with me.
那正是他对我生气的原因.（That's why…强调结果）
what引导的主语从句表示结果或名词reason作主语时,后面的表语从句表示原因时要用that引导,不宜用because.