精选优质文档-倾情为你奉上It作形式主语常见句型四川省乐至中学 张与刚动词不定式,动名词或主语从句作主语时,通常把它们放在谓语动词前,而用it作形式主语,放到句首,常见句型有:1. It + be + 形容词+主语从句,如:It is uncertain whether he can come to Jennys birthday party or not.2. It + be + 名词词组 + 主语从句,这类名词有:a fact, a pity, a shame, an honour,a question等,如:Its a pity that you missed the exciting football match.It remains a question whether he will come or not. 3. It + be + 过去分词 + 主语从句,这类过去分词有:announced, believed, expected, hoped, decided, reported, said, shown等, 如: