Sb is said/believed/known等后接动词必须用不定式,不能改用现在分词。当不定式的动作与谓语动作具有同时性时,则不定式需要用进行体。
Huddleston著《剑桥英语语法》将这种结构称为提升主语(raised subject),即一个分句的主语被提升到高一级的分句中作主语。原句是下面这样的。
It is said/believed/known that sb does/did/has done/is doing sth.
被动语态的主语为that分句整句的内容,而不仅仅是that分句的主语sb. 该句型可以转换如下:
1 用that从句中主语作主句的主语,但此时主语被动语态谓语动词语义不完整;
2 将that从句的谓语动词改为不定式,作主句中被动语态的主语补足语(只能用不定式)。
3 如果原that从句谓语动词为静态动词的一般体,则不定式用一般体to do (不定式表示的状态与主句谓语时间为同时性);如果that从句谓语为动态动词表示事件,该事件发生的时间先于主句谓语时间,则不定式用完成体to have done; 如果该时间与主句谓语为同时性,则不定式用进行体;如果that从句谓语为习惯意义,则不定式也用一般体to do.
由此得到提升主语的句子:
Sb is said/believed/known to do/to have done/to be doing sth.
注意to do通常为静态动词表示状态,或动态动词表示习惯(静态意义)。to have done表示不定式动作先于谓语时间。to be doing表示该事件(动作)与谓语时间是同时的。
这种结构不可以使用现在分词作主补。
consider后接复合宾语时,有以下三种句型:
consider sb/sth (as) sb/sth (as后只能接名词,as可有可无)
He considers himself (as) an expert on the subject.
consider sb/sth (to be) + 名词或形容词 (如果名词作to be的确认性表语时,to be不可省略。表语为归属性时,to be可有可无)
This award is considered (to be) a great honour.
Who do you consider (to be) responsible for the accident?
We considere him to be the man to do the job. (to be不可省略)
consider sb/sth to do (不定式通常须为静态动词表示状态)。
He's generally considered to have the finest tenor voice in the country.
联系客服