初中动词不定式专题讲解及练习

语法：动词不定式

动词不定动式是一种非谓语动词形式，它没有人称和数的变化，在句子中不能作谓语，但可以作除谓语之外的其它任何句子成分（主语、表语、宾语、宾语补足语、定语和状语）；动

词不定式具有名词、形容词和副词的特征，同时还保持动词的某些特点，既可以有自己的宾语和状语，动词不定式和它的宾语和状语构成不定式短语。

一、构成：to do .否定式not to do

二、常见时态：一般时to do 进行时to be doing 完成式to have done

完成进行式to have been doing

三、动词不定式在句子中的成分

1、作句子的主语：现实中常用it作形式主语，而把真正的主语动词不定式（或短语）

后置。

比较下列句子

To learn from your friends is important.=It is important to learn from your friends .

To leave without saying goodbye is impolite.= It is impolite to leave without saying

goodbye.

To chat with Miss White is a pleasant thing.=It is a pleasant thing to chat with Miss

White.

To walk to school takes me ten minutes.=It takes me ten minutes to walk to school.

句型总结

在以某些表示人的品质、

sb. is are +adj. +to do…

It is + adj. + of sb. to do…=

特征等的形容词（如kind、good、nice、wrong、clever、right等）作表语时，不定式之前常加一个引起的短语，说明不定式指的是谁的情况（可以理解为某人的好，坏，聪明，愚蠢，

对，错等等）。

It is very kind of you to help me.

It’s not polite of him to speak to old people like that.

如果要说明不定式表示的

are +adj. +to do…

It is + adj. + for sb. to do…≠ sb. is

动作是谁做的，则在不定式前加一个for引起的短语，即不定式的逻辑主语。

It is necessary for us to study hard.

It is easy for him to speak English.

动词不定式作主语练习

1. It's our duty _________ the room every day.

A. to clean

B. cleaned

C. clean

D. cleans(甘肃省)

2. It's hard for us _____ English well.

A. learn

B. learns

C. to learn

D. learning(江西省)

3.建造这座立交桥将花费工人们一年多的时间。

It will ______the workers over a year _____ ____the flyover.(北京市海淀区)

4. It's very nice _____you to get me two tickets _________ the World Cup.

A. for，of

B. of，for

C. to，for

D. of，to(安徽省)

KEYS: 1. A 2.C 3. take, to build 4. B

2、作句子的表语：不定式放在be 动词后面，用作表语如：

Her dream is to be a policeman.

My job is to help the patient.

Your task is to clean the classroom.

My dream is to own a robot.

to take more exercise.

The doctor’s suggestion is

The best way is to talk to your parents.

His plan is to travel to Beijing this summer.

My purpose is to help you solve this problem.

3、作句子的宾语：不定式放在及物动词后，用作宾语。能跟不定式作宾语的动词（及物）

很多，常见的有want, like, hate, wish, hope, prefer, try, ask, start, begin, decide, learn,

choose, agree, expect, remember, forget, plan, decide, would like, need, choose, agree, promise, refuse, set out, manage, pretend,

I want to go home.

The workers demanded to get better pay.

They began to read and write.

She forgot to close the door.

He wanted to borrow my CD player.

I hope to speak English well.

The workers demanded to get better pay.

I hope to hear from you soon.

John doesn’t

want to be the host of the charity show.

They are trying to solve the problem by himself.

Millions of people have learned to use computers.

有些动词既可跟不定式作宾语，也可跟动名词作宾语，但含义不同：

forget to do sth.忘记要做某事

forget doing sth.忘记曾经做过某事

stop to do sth. 停下来去做某事

stop doing sth.停止做某事