英语语法名词性从句知识：表语从句用法详解

　　一、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 fact is that he doesnt really try. 事实是他没有做真正的努力。

　　The trouble is that I have lost his address. 麻烦的是我把他的地址丢了。

　　My suggestion is that we should tell him. 我的建议是我们应该告诉他。

　　His sole requirement was (is) that the system work. 他唯一的要求是这个制度能起作用。

　　My idea is that we should start making preparations right now. 我的意见是我们马上就开始做准备工作。

　　2. 由whether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。

　　3. 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。

　　The problem is who we can get to replace her. 问题是我们能找到谁去替换她呢。

　　The question is who (m) we should trust. 问题是我们应当相信谁。

　　What I want to know is which road we should take. 我想知道的是我们应走哪条路。

　　4. 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。

　　That was when I was fifteen. 这是我15岁时发生的事。

　　Thats where I first met her. 那就是我第一次遇见她的地方。

　　Thats why he didnt come. 这就是他没有来的缘故。

　　Thats why I object to the plan. 这就是我反对这个计划的原因。

　　Thats where you are wrong. 这就是你不对的地方。

　　5. 由关系代词型what引导

　　Thats what I want to stress. 这是我想强调的。

　　Thats what we are here for. 我们来这里就为了这个。

　　Fame and personal gain is what theyre after. 他们追求的是名利。

　　He is no longer what he was. 他已经不是以前的他了。

　　6. 由as if / as though引导

　　It isnt as if you were going away for ever. 又不是你离开不回来了。

　　Now it was as though she had known Millie for years. 现在好像她认识米莉已有好多年了似的。

　　It is not as though we were poor. 又不是我们家里穷。