精选优质文档-倾情为你奉上It作形式主语常见句型动词不定式，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：It is reported
