动词不定式知识点

非谓语动词之动词不定式
动词不定式
一．定义：在句中充当除谓语以外的句子成分的动词形式。

二．动词不定式结构：肯定结构:to do否定结构not to do(to有时省略) 三．动词不定式的功能：动词不定式在句子中可以作主语、宾语、宾补、表语、定语、状语.
四．动词不定式的用法
（一）.动词不定式作主语：动词不定式作主语常作单数，其后谓动词也用单数
To learn English well is not easy.
To walk in the morning is good for us.
这两个句子里面不定式充当的是主语，但是在现代英语中，不定式作主语，头太重了，为了避免这种头重脚轻的现象，常用it作形式主语，真正的主语是后边的动词不定式
常考结构：it作形式主语，动词不定式作真正的主语。

It’s+adj to do sth.做某事是怎样的。

It’s easy to study English.
It’s+adj for sb to do sth.对于某人来说做某事是怎样的。

It’s important for us to study English.
区分这个结构
It’s+adj of sb to do sth.某人太...怎么样做某事。

It so kind of you to help me.你太好了帮助我。

（二）.动词不定式作表语：动词不定式作表语用于系动词（be）的后面
Linda seems to be happy today.
My dream is to be a teacher.
My job is to teach students.
（三）动词不定式作宾语
1.动词+to do sth
积累动词：want/would like想要/need需要/plan计划/hope希望/ wish希望/expect期待，期望/like喜欢/love喜欢agree同意/decide决定等等
like to do sth喜欢做某事 love to do sth喜欢做某事
want to do sth想要做某事 would like to do sth想要做某事
begin to do sth开始做某事 start to do sth开始做某事
remember to do sth记得去做某事 forget to do sth忘记去做某事
plan to do sth计划做某事 mean to do sth计划做某事
need to do sth需要做某事 stop to do sth停下来去做另一件事
hope to do sth希望做某事 wish to do sth希望做某事
expect to do sth期望做某事 agree to do sth同意做某事
decide to do sth决定做某事 promise to do sth承诺做某事
offer to do sth 主动做某事 volunteer to do sth自愿做某事
fail to do sth 未能做某事 afford to do sth负担得起做某事
prefer to do sth更喜欢做某事 regret to do sth后悔去做某事
help to do sth=help do sth帮助做某事
注意：如果and连接两个动词不定式,第二个动词不定式一般省“to”
He wants to go and have a swim with us.
他想和我们一起去游泳.
2.若作宾语的动词不定式很长,可用it作形式宾语. 动词+it+adj(for sb)to do sth make/find/think +it+adj(for sb)to do sth
I find it interesting to learn English with you.
我觉得和你一起学英语很有趣.
He found it hard to catch up with others.
他觉得赶上别人很困难.
（四）动词不定式作宾语补足语放在宾语后，有三种情况
1.动词+sb to do sth.
积累动词：want/would like想要/allow允许/ask询问/wish希望/expect期待，期望/tell告诉order命令/advise建议等等
want sb to do sth 想要某人做某事would like sb to do sth想要某人做某事allow sb to do sth允许某人做某事ask sb to do sth要求某人做某事
request sb to sth要求某人做某事require sb to do sth要求某人做某事
wish sb to do sth希望某人做某事expect sb to do sth期望某人做某事
tell sb to do sth告诉某人做某事teach sb to do sth教某人做某事
order sb to do sth命令某人做某事advise sb to do sth建议某人做某事
invite sb to do sth邀请某人做某事encourage sb to do sth鼓励某人做某事
2.跟不带to的的不定式作宾补：动词+sb+ do sth
使役动词和感官动词
let sb do sth 让某人做某事 have sb do sth 让某人做某事
make sb do sth 让某人做某事 see sb do sth 看见某人做某事
watch sb do sth看见某人做某事 hear sb do sth听见某人做某事
notice sb do sth 注意某人做某事 feel sb do sth感觉某人做某事
3.可跟to或不跟to的不定式作宾补
help sb do sth帮助某人做某事help sb to do sth帮助某人做某事
（五）.动词不定式作定语：动词不定式作定语常用来修饰名词或不定代词,放于所修饰的词后,为后置定语
I have some work to do.我有一些要做的工作。

Would you like something to eat?你想要吃的一些东西吗?
The best way to learn English is to use it.学英语最好的方法是使用它. （六）.动词不定式作状语：
They got up early to catch the early bus.他们早起去赶早班车.
I come here to study.他来这为了学习。

I am sorry to trouble you.很抱歉麻烦你。

（七）不定式和疑问词连用,可以作句子的主语、宾语、表语等.
特殊疑问词+to do sth
The problem is where to get a computer. （表语）
No one knows how to do it.
没有人知道如何做这件事.（宾）
When and where to have the party is not known. （主语）
何时何地举行联欢还不知道.
（八）记住常考动词不定式结构：
1.too....to太...而不能做某事
It’s too dark黑暗的for us to see anything.对于我们来说太黑了什么也看不到。

She is too young to go to school.她太年轻了不能去上学。

2.形容词/副词+enough to do sth足够怎么样去做某事
She is old enough to go to school.她足够大可以去上学。

3.It is time to do sth 做某事的时间到了
It is time for us to do sth对于某人来说做某事的时间到了
eg：It’s time to have lunch.
4.It takes sb +一些时间/金钱 to do sth.做某事花费了某人多长时间/多少金钱.
5.It is one’s turn to do sth轮到某人做某事
6.in order to do sth为了做某事。