Unit 1语法—动词不定式to do讲义2026-2027学年人教版英语八年级下册

英语人教版八年级下册Unit 1语法讲义——动词不定式to do

 一、动词不定式的构成

肯定结构：to + 动词原形 → to do

- 没有人称和数的变化

- 属于非谓语形式

 

否定结构：not to do

 

 二、动词不定式的用法

to do在句中可以作主语、宾语、宾语补足语、状语、表语、后置定语。

1、to do 作目的状语

常用结构：主句 + to do sth（不定式放句末，无逗号）

例：I got up early this morning to catch the bus.

 

强调结构：To do sth, 句子.（不定式放句首，后加逗号）

例：To relax, Chen Jie plays the flute in her free time.

 

2、to do 作宾补

结构：V + sb/sth + to do sth

用来补充说明宾语所做的动作。

常用动词：tell, ask, want, teach, promise, wish, invite, allow, encourage, want/would like, expect, advise 等 + sb to do sth

例：My mother asks me to clean my room.

 

特殊：不带to（省略to）的不定式作宾补

结构：V + sb/sth + do sth

口诀：一感feel；二听hear / listen；三让let / make / have；四看look / see / notice / watch；半个帮助help sb (to) do sth

例：I saw my mother paint.

 

3、to do 作宾语

结构：V + to do sth

接在表示“计划、决定、想要”等动词后，作该动词的宾语。

常接动词不定式作宾语的动词：

想要、拒绝、忘记（want, refuse, forget）

需要、努力、学习（need, try, learn）

选择、同意、帮助（choose, agree, help）

希望、决定、开始（hope/wish/expect, decide, begin/start）

 

特殊：不定式to do作真正的宾语

结构：Sb find / feel / think / make / consider it adj/n to do sth

例：I find it really difficult to play the violin.

 

4、to do 作主语

例：To learn English well is important for us.

⇒ It is important for us to learn English well.

It为形式主语，to learn English well是真正的主语。

固定句型：It is adj (for sb) to do sth.

 

5、to do 作表语（主语常为dream, job, hobby等）

例：My hobby is to swim.

 

6、“疑问词 + to do”结构

例：My grandmother taught me how to write it.

 

7、to do 作后置定语

例：a good way to do sth

例：a perfect place to do sth

例：Would you like something to drink?

 

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 配套练习题

 一、单项选择

1. My mother tells me ____ late for school.

A. not be  B. not to be  C. don’t be  D. won’t be

 

2. I hope ____ a doctor in the future.

A. be  B. to be  C. being  D. been

 

3. It’s important for us ____ English every day.

A. practice  B. practicing  C. to practice  D. practiced

 

4. She made me ____ the housework on Sunday.

A. do  B. to do  C. doing  D. done

 

5. I have a lot of homework ____ tonight.

A. do  B. doing  C. to do  D. did

 

6. —Why did you get up so early?

—____ catch the first bus.

A. For  B. To  C. So  D. With

 

7. He wants to know ____ use the new machine.

A. how to  B. what to  C. where to  D. who to