8下Unit4语法知识点讲解与练习

最新牛津译林版 8下Unit 4语言点知识点讲解与练习

本单元语法知识

一、“特殊疑问词＋动词不定式”的用法归纳

（一）由两部分构成：疑问词和动词不定式（wh-+to do）。疑问词部分包括疑问代词who, whom, what, which和whose以及疑问副词when, where和how。此外，连接词“whether”也适用.它 主要具有以下几种功能：

⑴当主语，如：

● When to hold the meeting has not yet been decided.

● Where to live is a problem.

⑵当宾语，常接在forget, find out, discuss, decide, tell, teach, know, learn, wonder, remember等动词之后作宾语如：

● We must know what to say at a meeting.

● He could not tell whom to trust.

● Do you know how to play bridge?

　⑶当表语，如：

● The problem is where to find the financial aid.

● The question is who to elect.

⑷当名词同位语，如：

● Tom had no idea which book to read first.

● The question whether to confess troubled the girl.

⑸用于宾语补足语,双重宾语。某些动词后可接“sb.+ 疑问词 + 不定式”构成的双重宾语，这类动词常用的有advise, ask, show, teach, tell等如：

● I can tell you where to get this book.

● I ask her how to learn English.

● He will advise you what to do.

● Will you show me how to use the machine?

(6) 作介词宾语：某些介词后面可接"疑问词＋不定式"作宾语，这类介词常用的有 about, as, from, in, of, on, with等。例如：

He has no idea of how to answer this question. 他不知道怎样回答这个问题。

Della had only $1.87 with which to buy Jim a present. 德拉仅有$1.87为来吉姆买一件礼物。(which是关系代词)

You have a number of topics from which to choose. 你有很多题目可以选择。(which是关系代词)

（二）“特殊疑问词＋动词不定式”这种结构可以把复合句转为简单句。

如： I don’t know what I’ll do next. = I don’t know what to do next.

 The doctor told him when he should take the medicine. = The doctor told him when to take the medicine.

同样，因为“特殊疑问词＋动词不定式”这种结构相当于一个名词性从句，所以可用同等成分的从句代替，从而把简单句转换为复合句。改写时只需在疑问词后加上适当的主语，并把不定式改为适当的形式的谓语即可。如：

Which to choose is important. = Which we should choose is important.

 The question is where to go. = The question is where we should go.

 （三）“特殊疑问词＋动词不定式”这种结构可构成独立问句。如：

  What to do? 怎么办？

How to get rid of the trouble? 如何摆脱困境？

按照英语语法的习惯，疑问副词why 后不直接跟动词不定式，如：

误：I don’t know why to choose that dictionary.

正：I don’t know why you must choose that dictionary.

但它可以接不带to的动词不定式，即动词原形，构成why do sth./ why not do sth. 肯定形式是表示某动作是不必要的或没有意义的，而否定形式是表示向某人提建议和表达看法，相当于祈使句。

Today is Sunday. Why not go out to relax yourself?

Why pay more at other shops? We have the best value.

练习一：

( )1.I  have no idea when _________  her the bad news.

A. will  tell           B. telling                C. tell             D. to  tell

( )2. ---Will you please show me how to do the role-play exercise?

---Sure. Now let me tell you ________ first.

A. which to do B. how to do C. when to do D. what to do

( )3. I need your help because I don’t know ________.

A. how to do it B. how to do C. what to do it D. what should I do

( )4.---How are you feeling here?

---It’s quite hot. I don’t know ________ to go or stay.

A. how B. when C. whether D. where

( )5.---I don’t know ________ to do with this maths problem. It’s too hard.

--- You can ask your classmates or teachers for help.

A. which B. how C. what D. when

( )6. ---Millie, could you give me some advice? I don’t know ________.

--- Why don’t you wear this red shirt?

A. when to wear B. what to wear C. how to wear D. where to wear

( )7. I’m going on a field trip but I haven’t decided________.

　　 A. what to do B. to do what 　　 C. where to go D. to go where

( )8 ---This physics problem is too difficult. Can you show me ________，Wang Lin？

　　 ---Sure.

　　 A. what to work it out 　　B. what to work out it C. how to work it out 　D. how to work out it

( )9. Excuse me. Would you please tell me ________ buy a digital camera？

　　 A. what to B. where to C. what I can D. where can I

( )10. There isn't any difference between the two. I really don't know ________.

　 A. where to choose 　B. which to choose 　C. to choose what D. to choose which

二、动词不定式做宾语补足语

(1)常接带to的动词不定式作宾语补足语的动词有：ask, tell, want, teach, wish等；

(2)接不带to的动词不定式作宾语补足语的动词有：see, watch, hear, make, let advise, allow, ask, beg, command, tell, invite, force, oblige, get, help, encourage, persuade, permit, remind, request, order, warn, cause等。

例如：I often see him play football.

She often asks me to help her.

We don't allow such things to happen again.

Most of the parents agree to forbid their children to smoke.

She asked me to answer the phone in her absence.

Please remind me to leave her this note.

She requested him to go with her.

（3）用不定式作宾语补足语的几种说明：

①help后面作宾语补足语的动词不定式可以带to也可以不带to。

如：I often help my mother (to) do some housework.

②在使役动词后作宾语补足语，不定式不带to。有些动词跟不定式作宾语补足语时省去了to，这些动词有：一感二听三让四观看。　

一感：feel　 二听：hear, listen to　

三让：let, have, make 四观看：notice, see, watch, look at

这类动词有：make, let, have等。转为被动语态时，其后通常都用带to的不定式 （have没有被动语态）。　　

例如：What would you have me do?

Let him do whatever he wishes to do.

Though he had often made his little sister cry, today he was made to cry by his little sister.

　（4）不定式作宾语补足语的有以下八种类型：

① 许多动词可跟一个宾语 + to do…构成句子，句中的不定式作宾语补足语；否定形式为“动词+宾语+not to do…”。

例如：My boss told me to type out two letters.

分析：句中“My boss”做主语，“told”作谓语，“me”作宾语，划线部分作宾语补足语。请看下面的句子。

They forbade her to leave the country.

Please remind me not to be late for the meeting.

适用于“动词+宾语+(not)to do…”的结构，不定式作宾语补足语的动词有：advise，allow，ask，beg，cause，direct，encourage，expect，forbid，force，invite，order，permit，persuade，remind，re-quest，require，teach，tell，want，warn等。

② 有些动词可跟“宾语+to be…”构成句子，句中的不定式作宾语补足语。

例如：I consider him to be the best candidate.

分析：句中“I”做主语，“consider”作谓语，“him”作宾语，划线部分作宾语补足语。请看下面的句子。

I know him to be a liar.

I suppose him to be away from home.

适用于“动词+宾语+to be…”的结构，不定式作宾语补足语的动词有：consider，declare，discover，feel，find，suppose等。

③ 有些动词(感官动词和使动词)后可跟不带to的不定式构成句子，句中的不定式作宾语补足语。

例如：He saw her enter the room.

分析：句中“He”做主语，“saw”作谓语，“her”作宾语，划线部分作宾语补足语。请看下面的句子。

She won't let me do it.

I heard her lock the door.

We watched the children play games.

适用于“动词+宾语+do…”的结构，不定式作宾语补足语的动词有：feel，have，hear，let，make，notice，observe，see，watch等。还有两个词组：listen to，look at.

④ help后的不定式可加to，也可不加to(美国人不加to时较多)，但被动结构中要加to。

例如：I'll help you(to) push the cart.

分析：句中“I”做主语，“will help”作谓语，“you”作宾语，划线部分作宾语补足语。

上句的被动语态为：You'll be helped to push the cart.

⑤ 有些“动词+介词”的结构后也可跟不定式构成句子，句中的不定式作宾语补足语。

例如：He shouted to me to come over.

分析：句中“He”做主语，“shouted”作谓语，“to”为介词，“me”作宾语，划线部分作宾语补足语。请看下列句子，句子的结构为“动词+介词+宾语+to do…”，划线部分为不定式，作宾语补足语。请看下面的句子。

I depend on you to do it.

I am counting on you to help me through.

适用于“动词+介词+宾语+to do…”的结构，不定式作宾语补足语的动词有：shout to sb.to do，call on sb. to do，count on sb. to do，depend on sb. to do，wait for sb. to do等。

⑥ 作宾语补足语的不定式，表示的动作在谓语所表示情况之前发生，就需要用完成形式：

例如：He was known to have worked for the International Olympic Committee.

分析：句中“He”做主语，“was known”作谓语，使用了被动语态。由句意可知，“为国际奥委会工作”发生在前，“大家知道”发生在后。故不定式部分用完成形式，在句中作宾语补足语。

⑦ 作宾语补足语的不定式，表示一个正在进行的动作时需用进行形式：

例如：He is believed to be living in Mexico.

分析：句中“He”做主语，“isbelieved”作谓语，使用了被动语态。由于句子表达主语现在正在发生的情况，故用不定式的进行形式，句中划线部分作宾语补足语。请看下列句子。

Thousands were reported to be working in concentration camps.

He is thought to be hiding in the woods.

间或不定式作宾语补足语也可用于完成进行时。例如：

She is said to have been doing this work for twenty years.

⑧ 不定式作宾语补足语的被动形式：

例如：He didn't want her son to be taken away.

分析：句中“She”做主语，“didn't want”作谓语，“her son”作宾语，由于“her son”与“take away”之间为被动关系，故用被动形式，句中划线部分作宾语补足语。

宾语补足语练习题

( )1. ---“Did you have any difficulty in today’s homework?”

---“No, in fact I found __________.”

A. it very easy to do B. it very easy done C. very easy for doing D. very easy to do it

( )2. ---There’s a hole in your bag.

--- I know, I’m going to have it _____.

A.mend B. mending C. mended D. to be mended

( )3. Though he had often made his little sister ________, today he was made ____ by his little sister.

A.cry; to cry B. crying; crying C. cry; cry D. to cry; cry

( )4. They would not allow him ________ across the enemy line.

A.to risk going B. risking to go C. for risk to go D. risk going

( )5. I found the door _________ when I got home.

A.opened B. close C. unlocking D. open

( )6. The boy wanted to ride his bicycle in the street, but his mother told him _________.

A.not to B. not to do C. not do D. do not to

( )7. I couldn’t do my homework with all that noise__________.

A.going on B. goes on C. went on D. to go on

( )8. With a lot of difficult problems__________, the newly-elected president is having a hard time.

A. solved        B. solving       C. to solve     D. being solved

( )9. I advised _________ at once.

A.him to starting B. him to start C. to starting D. to start

( )10. When I put my hand on his chest, I could feel his heart still __________.

A.beat B. to be beating C. beating D. was beating

( )11. You had better get a doctor _________ your bad tooth.

A.pull out B. to pull out C. pulled out D. pulling out

( )12. He managed to make himself ________with his_________ English.

A.understand; breaking B. understand; broken

C. understood; breaking D. understood; broken

( )13. The doctor asked him not to leave his wound __________.

A. expose B. exposed C. to expose D. exposing

( )14. They are going to have the service man _________ an electric fan in the office tomorrow.

A. install 　　 B. to install 　 C. to be installed 　 D. installed

( )15. After a few rounds of talks, both sides regarded the territory dispute(领土争端) _________.

A.being settled 　B. to be settled C. had settled 　　 D. as settled

( )16. You will see this product made in this factory _________ wherever you go.

A.to be advertised B. advertised 　C. advertise 　　 D. advertising

( )17. His remarks(评论) left me _________ about his real purpose.

A.wondered 　 B. wonder 　　 C. to wonder 　　 D. wondering

( )18. When I caught him __________ me I stopped buying things there and started dealing with another shop.

A.cheating B. cheat C. to cheat 　　 D. to be cheating

( )19. Though he had often made his little sister ________, today he was made ________ by his little sister.

A. cry; to cry B. crying; crying C. cry; cry D. to cry; cry

( )20. Did you intend(想要某人做事) us _________ the new method?

A. using B. to use C. using D. are using

( )21. The teacher encouraged us __________ good compositions.

A. Writing B. written C. to write D. is writing

( )22. The boy wanted to ride his bicycle in the street, but his mother told him ___________.

A. not to B. not to do C. not do it D. do not to

( )23. Mrs. Brown was much disappointed to see the washing machine she had had _______went wrong again.

A .it B. it repaired C .repaired D. to be repaired

( )24. With a lot of difficult problems_________, the newly—elected president is having a hard time.

A .settled B. settling C. to settle D. being settled

( )25. With trees, flowers and grass_________ everywhere, my native town had taken on a new look.

A. planting B. planted C. to plant D.to be planted

( )26. She was glad to see her child well_________ care of.

A. take B. to be taken C. taken D. taking

( )27. The result of the entrance exams was not made _________to the public until last Thursday.

A. knowing B. known C. to know D. to be known

( )28. I can make you _________what I say, but you can’t make yourself _________ in English.

A. understand; understand B .understand, understood

C. to understand, understand D. understand; to be understood

( )29. He found them ________ at a table_________.

A. sat; to play chess B. sitting; to play chess

C. seated; playing chess D. seat; play the chess

( )30. John rushed out in a hurry, _________ the door_________.

A. leaving; unlocked B. leaving; unlocking

C. left; unlocked D. to leave; unlocking

( )31. We are pleased to see the problem_________ so quickly.

A. settled B. settling C. be settled D. having been settled

( )32. I could feel the wind _________on my face from an open window.

A .to blow B .blowing C. to be blowing D .blown

( )33. ________ production up by 60%,the company has had another excellent year.

A. As　　 B. For 　 C. With　 D. Through

( )34. ________ everything _________ , she left the supermarket with satisfaction.

A. As, buying B. For, to buy C. With, bought D .Because, to buy

( )35. Don’t leave the water ________ while you brush your teeth.

A. run B. running C. being run D. to run

(二)must和have to用法比较讲解

（1）must表示“必须”，“应该”。否定式must not(mustn't)表示“不应该”，“不许可”，“不准”,“禁止”等。在回答带有must的问句时，否定式常用need not(needn't)或don't have to 表示“不必”，而不用must not (mustn't)。

The work must be finished as soon as possible.这件工作必须尽快完成。

You mustn't speak like that.你不能那样说话。

—Must I be home before eight o'clock? 8点之前我必须回家吗？

—Yes, you must./No, you needn't./No, you don't have to. 是的，必须回家。/不，不必了。

（2）must表推测，

①一般只用于肯定句中，译成汉语“一定”，“必定”。

There must be some mistakes.肯定有一些错误。 You must be very tired.你一定很累了。

②如果表示对过去事情的推测，就用"must+完成时"。

You must have left your umbrella in the theatre.你一定把雨伞丢在剧院里了。

His car is still here. He must have gone by bus.他的车还在这里，他一定乘公共汽车走了。

③当must表推测之意时，其否定形式常用can not而不用must not。

He can't have been to your home. He doesn't know your address.他不可能到过你家，因为他不知道你的住址。

What can he be doing at this time of night?夜晚都到这个时候了，他究竟在干什么呢?

（3）must表必然性

You must catch cold if you don't put on more clothes.如果你不多穿些衣服，必然感冒。

All men must die.人固有一死。 Truth must be out.真相总会大白。

（4）have to表示“必须”，“不得不”，在这个意义上与must很接近，但must表示的是说话人的主观看法，而have to 表示的却是客观需要。

I have to go now.我得走了。（客观需要） I must go now.我必须走。（主观看法）

You have to work hard to make a living.为了谋生你就得努力工作。（客观需要）

You must do what I tell you.你必须按照我告诉你的去做。（主观要求）

（5）have to 有更多的时态形式：现在时，过去时，将来时等，而must只有现在时形式。

We had to be there at 8.我们得8点到那里。

I shall have to go to school tomorrow.明天我得去上学了。

（6）have to 不能代替表推测的must，但在虚拟条件句中用had had to+动词原形表示与过去相反的情况。

You must be joking.你一定是在开玩笑。（不能用have to）

If I had had to do the work, I should have done it in a different way.

如果我不得不做这项工作，我会以不同的方式去做。（不能用must）

If I had had to run the factory, I would have had it run by able men.如果我得管理那家工厂的话，我就会让能人来管。（不能用must）

 练习三

( )1. ---Must I do it now? ---No, you __________.

A. needn’t B. don’t have to C. mustn’t D. A or B

( )2. My bike is broken, I __________ walk to school today.

A. must B. can C. have to D. may

( )3. You _________ learn English well, bcause it’s very important for you.

A. must B. can C. have to D. may

( )4. Jim isn’t at school today, I think he ___________ be ill.

A. must B. can C. has to D. may

( )5. ---Must I finish the work at once? ---No, you _________.

A. mustn’t B. can’t C. don’t have to D. have to

( )6. Mrs. Brown was ill, she __________ see the doctor right away.

A. must B. had do C. could D. might

练习一：1—5DDADC 6—10BCCBB

练习二：1—5ACAAD 6—10BACBC 11—15BDBAD 16—20BDAAB 21—25CBBCB 26—30CBBCA

31—35ABCCB

练习三：1—5DCAAC 6. B

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