Section A 2d—3c精品学案

八年级英语上册

Unit 5 Grammar Focus动词不定式的用法

【学习目标】掌握动词不定式的种类和用法

【学习重、难点】动词不定式的用法

【语法探究】

定义：1.动词不定式是由“不定式符号to+动词原形”构成的一种非谓语动词结构。有些动词不定式不带to。

2.动词不定式没有人称和数的变化，可以作句子的主语、表语、宾语、定语、补语、状语

用法：

To learn English well is not easy. –--不定式作_________

I want to learn English well . –--不定式作_________

My dream is to learn English well .

–--不定式作_________

I have many things to do. –--不定式作_________

She came here to study English.

–--不定式作_________ My mother asks me to learn English well . –--不定式作_________ 一、用作主语

多数情况用it作形式主语，把真正的主语——动词不定式置于句末，特别是不定式短语较长时。动词不定式作主语，谓语动词用第三人称单数形式。

It is important to learn English.学习英语是重要的。To learn English is noteasy. 二、用作表语

动词不定式作表语，常说明主语的内容、性质、特征。如：

The first thing is to listen to the teacher carefully.

三、用作宾语

1.可以接带to的动词不定式作宾语的动词主要有：

需要拒绝莫忘记(need, refuse, forget) 如：

想要学习就努力

(want, learn, try)

希望帮助并同意(hope\wish, help, agree)如：I wish to visit Mexico. 喜欢决定后开始(like, decide, begin\start) 如：We decide to go to the movies tonight. 2. Know, ask, show, teach, guess, find out等动词短语后可用“疑问词+动词不定式结构”

Eg. Please teach me how to play the piano.请教我怎么弹钢琴。

3.动词feel, find, make, think等后面，可以用it作形式宾语代替真正的宾语——动词不定式，句子结构是...feel / find / make / ... it+adj. / n.+to do...。如：I find it difficult to learn English.

四、用作定语

1)I have so many clothes to wash today. 2)We have no houses to live in. 五、用作宾语补足语

1.带to的动词不定式作宾语补足语的动词主要有：

要求允许提议(ask, allow, advise)，期望邀请鼓励(expect, invite, encourage)，教导告诉想要(teach, tell, want)，等待希望愿意(wait for, wish, would like / love)。如：

1) I invite her to have dinner at my house.

2.动词不定式作补语，在主动语态句里不带to，被动语态句里带to时多数动词是感官动词和使役动词，包括四“看”：look at, observe, see, watch，三“让”：have, let, make，二“听”：hear, listen to，一“感觉”：feel，一“注意”：notice。如：

1)This picture makes me feel excited！

2)We saw Liu Yu play baseball last week. 3.help后接动词不定式作补语，to可带可不带。

1) they can help you to learn English.

2)Using email English helps you write quickly.

六、用作状语

1.目的状语，置于句首或句末，置于句首时常表示强调。如：

1)In order to catch the early bus, she got up very early. 2)She came to this city to visit her daughter. 2.原因状语，多见于“sb.+be+adj.+to do...”结构句中。如：

1) I feel very lucky to have him. 2) he ran out of money to buy old bikes.

3.结果状语，多见于“too...to”，“enough to...”结构句中。如：

1) I’m too tired to do it well.

2)The room is big enough for three people to live in.

七、动词不定式的否定式

不定式的否定式是not / never to do...，不带to的不定式的否定式是not / never do...如：

Eg.1.They decide not to talk to each other.

2.His parents tell him never to play soccer in the street.

【当堂练习】

I．选择题

1. Paul said, "Give me a chair _____." A. to sit

B. sit

C. sit on

D. to sit on 2. ---- Where did he go? ---- He went to another store ______.

A. to buy pencils

B.for buying pencils

C. buy pencils

D. buying pencils 3.That box is____.

A. too heavy for me to carry

B. too heavy for me to carry it

C. so heavy for me to carry

4. Last summer I took a course(上了一门课程) on ______ .

A. how to make dresses

B. how dresses be made

C. how to be made dresses

5. The house is not large enough ____ .

A. to live in

B. to be lived in

C. to live

D. for living 6. Now we could not do nothing but ______ for him here.

A. waited

B. waiting

C. to wait

D.wait 7.I expect the bus

_____ quickly, or I will be late.

A. come

B. to come

C. coming

8. He told her ______ there at once.

A. get

B. gets

C. to get 9. We all think it most foolish ______ this mistake.

A. for you making

B.of you to make

C. you to make

10. I really don't know ____ .

A. to swim

B. how to swim

C. how swim II.用所给单词的适当形式填空。

1. It is very hard for you _________________ (understand) this story. 2. After ______________ (think) everything over, she decided ______________ (not send) her letter. 3. He did not want____________ (see) him. 4. I saw him________________ (cry) in the classroom. 5. Let her ________________(do) her homework herself.