表语从句的引导词：
引导表语从句的词有连词that, whether，连接代词和连接副词，关系代词型what，以及as if, as though, because等连词。
1、 由that引导
The question is whether the film is worth seeing. 问题是这部电影是否值得看。
注意：whether 可引导表语从句，但与之同义的if却通常不用于引导表语从句。
2、由连接代词引导
You are not who I thought you were. 你已不是我过去所想像的人。
3、由连接副词引导
The problem is how we can find him. 问题是我们如何找到他。
4、由关系代词型what引导
He is no longer what he was. 他已经不是以前的他了。
5、由as if / as though引导
It is not as though we were poor. 又不是我们家里穷。