主语从句定义:在句子中担当主语的是一个从句,这个从句就叫做主语从句。
主语从句是在复合句中充当主语的从句,通常放在主句谓语动词之前或由形式主语it代替,而本身放在句子末尾。
It 作形式主语和it引导强调句的区别
①主语从句常用it作形式主语,一般常用句型为:It is+{名词/形容词/过去分词}+主语从句
例如:
It is still a question whether she will come or not.
It is strange that you should like him.
It is still unknown which team will win the match.
另外,还有一些比较多见的结构:
It turned out that……
It has been proved that……
It happened/occurred that……
It is well-known that……等等
②而强调句则不同,它的结构是:It+be+被强调部分+that+从句
强调主语:It is the times that produce their heroes.时势造英雄
强调宾语:It is English that teaches us.
强调状语:It was in shanghai that I saw the film.