表语从句一 定义：表语从句就是用一个作为表语。说明主语是什么或者怎么样，由、形容词或相当于名词或形容词的词或充当，和连系动词一起构成二引导表语从句的关联词的种类：(1) 从属连词that。在从句中不做成分。如：The trouble is that I have lost his address.麻烦是我把他的地址丢了。The reason was that he was late for school.原因是他上学迟到了(2) 从属连词whether, as, as if。如：1. He looked just as he had looked ten years before.他看起来还与十年前一样。2. The question is whether they will be able to help us. 问题是他们是否能帮我们。 注：（从属连词if一般不用来引导表语从句，但as if却可引导表语从句）。如：All this was
