北木教育 > 托福 > 托福文章 > TOEFL实用语法系列——如何理解长难句之非谓语动词2
发布时间:2018-09-14 北京智赢
定义:指动词的一种不带词形变化从而不指示人称、数量、时态的形式。它之所以被叫做不定式,是因为动词不被限定,或者说不被词形变化所局限。
简单来说,就是介词to后面跟动词原型,并可在句子中充当除谓语外的所有成份。
不定式做主语:To see is to believe.
不定式做宾语:I hope to see you again.
不定式做定语:See if you can get the car started.
不定式做状语:He went to the hospital to be examined.
不定式做表语:My work is to clean the room every day.
不定式还可跟在很多词后面:
疑问词+不定式:When to leave for London has not been decided yet.
形容词+不定式:He finds it hard to make friends.
名词+不定式:It’s our duty totake good care of the old.
代词+不定式:Give her something to eat.
动词+不定式:Don’t forget toturn off the lights.
介词+不定式:We have no choice but to wait.
由此可见,不定式在句子中,表示两种意思:表目的/表将来
比如want to do,想要做什么,表目的;
forget todo,表将来,不要忘了去做某事
不定式表否定:在不定式前加not或never即可,如:
Tell himnot to open the door.
注意:大多数动词后面接不定式,但也有例外,举几个常见的例子,其它的就要靠大家课下积累了:
直接跟do:let/make/have do
直接跟doing:enjoy/minddoing
均可,但表达意思不一样:
rememberto do(记得去做某事)/doing(记得做过某事)
forget todo(忘记去做某事)/doing(忘记做过某事)
to后面跟doing:look forward to doing/pay attention to doing/get used to doing
不定式还可表达被动语态和时态:
不定式可表被动:It’s an honor to be invited to your party.
不定式可表进行:He seems to be drinking something.
不定式可表完成:I'm sorry to have given you so much trouble.
不定式可表完成进行:She is known to have been wreaking on theproblem for many years.
总之,不定式的用法非常灵活,但有一点必须牢记,不定式,to do,不能做谓语。