文档介绍：Infinitives
动词不定式
不定式的构成
不定式的基本构成:to +动词原形
否定形式:not to +动词原形
不定式的特征
不定式是一种动词的非谓语形式,不能单独作谓语。
不定式分为带to的不定式和不带to的不定式
不定式有动词的特性,后可跟表语、宾语或状语,构成不定式短语
to be a teacher to do my homework
不定式具有名词、形容词、和副词的特征,在句中可作主语、宾语、表语、宾语补足语、状语、定语等
不定式的用法
1. 作主语
To see is to believe.
To learn English well is important.
当作主语的不定式较长时,可以用it作形式主语,变成It + be + adj. + to do sth.
或It + be + n. +to do
It is important to learn English well.
It’s not easy to learn French.
It’s our duty to keep our environment clean.
2. 作表语
To see is to believe.
My wish is to be a teacher.
3. 作宾语
常接不定式作宾语的动词有:want, wish, hope, forget, decide, agree, start, need, refuse, pretend, plan, intend, choose等
I want to buy a new dress.
We decided to go at once.
特殊疑问词+ 不定式(作宾语)
I don’t know what to do.
I want to know when to start the meeting.
Can you tell me how to get to the school?
4. 作宾语补足语
常接带to不定式作宾补的动词有:ask,
tell, order, encourage, invite, teach, want,
wish, allow, warn, persuade, advise等
She asked me to wait for her after school.
My mom told me not to play in the street.
接不带to的不定式作宾补的动词有:make,
let, see, hear, watch, notice等
Let him go.
I saw e in.
The boy made his sister cry.
help后可带to,也可不带to
She often helps her mother (to) do some housework.