【暑假提升】牛津译林版英语八年级（八升九）暑假-第03讲 疑问词+不定式作宾语和情态动词must, have to 讲学案

第03讲 疑问词+不定式作宾语和情态动词must, have to

【基础知识】

一、疑问词+不定式作宾语

宾语从句与简单句的转换：当宾语从句的主语与主句的主语相同时，从句可以简化为“疑问词+不定式” 结构。

如：I don’t know what I should do next. =I don’t know what to do next. 我不知道接下来要做什么。

注意：疑问词what, which, who, when, where, how及连接副词whether与不定式（to do）连用而形成一个短语，这个短语相当于一个名词，可在句中做句子宾语。

Do you know when to start?

你知道什么时候开始吗？

I showed her which button to press.

我告诉她应该按哪一个按钮。

有时还可用于介词后作宾语。

I found a book on how to avoid having a heart attack.

我找到一本书谈如何避免心脏病复发。

She was worried about how to fill her leisure time.

她为如何打发她的闲暇时间而发愁。

二、情态动词must, have to

（1）must 表示主观看法，意为“必须、一定”。

如：You must stay here until I come back.在我回来之前你必须呆在这儿。

注意区分must 和have to 的区别：

1. must 侧重说话者的主观看法，认为有必要有义务去做某事。have to侧重于客观需要，含有“不得不，被迫”之意。

如：My bike was broken yesterday, so I had to walk to school. 昨天我的自行车坏了，所以我只能走路去学校。

（2） 其否定形式mustn’t表示“ 一定不要 ” “千万别” “禁止, 不许”.

如：You mustn’t play with fire.  你不许玩火

（3）对must引导的疑问句，肯定回答为must，否定回答为needn’t  或 don’t have to .

如：Must I finish my homework?我现在必须完成作业吗？—No, you needn’t.不，你不必。

(4) must表示有把握的推测，用于肯定句。如: The light is on, so he must be at home now.

【考点剖析】

考点一： 疑问词+不定式作宾语

例1．（2022·山东·济南市天桥区教育教学研究中心中学教研科八年级期末）—Do you know how ________ a beef sandwich?

—Sorry, I don’t know.

A．makes B．to make C．making D．make

【答案】B

【详解】

句意：——你知道如何制作牛肉三明治吗？——对不起，我不知道。

考查非谓语动词。根据“Do you know how ... a beef sandwich?”可知，此处要用“疑问词+不定式”结构，故选B。

例2．（2021·黑龙江·讷河市教师进修学校八年级期末）The yellow one and the red one are very nice. Would you please advise   

me ________?

A．which to buy B．what to buy C．when to buy

【答案】A

【详解】

句意：黄色和红色的都很好。你建议我买哪一个？

考查疑问词+不定式。which to buy买哪一个；what to buy买什么；when to buy什么时候买，根据“The yellow one and the red one are very nice”可知，应该是不知道选哪一个，故选A。

例3．（2021·山东青岛·八年级期末）I don’t know ________ now.

A．to buy which book B．which book buying C．which book to buy D．buy which book

【答案】C

【详解】

句意：我现在不知道买哪本书。

考查疑问词+动词不定式结构。此处是“疑问词+动词不定式”作动词know的宾语，B选项which book to buy符合，故选C。

例4．（2022·山东青岛·八年级期末）—Have you made a decision when ________?

—Yes, tomorrow morning.

A．will you leave B．are you leaving C．to leave D．are you leave

【答案】C

【详解】

句意：——你决定什么时候走了吗？——是的，明天早上。

考查非谓语动词。疑问词+动词不定式作宾语，故选C。

考点二： 情态动词 must, have to

例5．（2021·四川成都·八年级期末）—Jacob, can you come to my Sweet 14 party tomorrow evening?

—Sorry, I_________ stay at home to look after my baby sister.

A．must B．could C．can’t

【答案】A

【详解】

句意：——雅各布，明天晚上你能来参加我的14岁甜蜜派对吗？——对不起，我必须待在家照顾我的小妹妹。

考查情态动词的辨析。must必须，一定；could可以，能够；can’t不能，不可能。由“stay at home to look after my baby sister”和“Sorry”可推出，“我”必须待在家照顾妹妹，不能来参加派对。故选A。

例6．（2021·河南·南阳市油田教育教学研究室八年级期末）— May I take this book out of the reading room?

—________. Please read it here.

A．Certainly B．No, you needn’t C．No, you mustn’t D．No, you may not

【答案】C

【详解】

句意：——我可以把这本书带出阅览室吗？——不，你不能。请在这里阅读。

考查一般疑问句及回答。问句是may开头的一般疑问句，这里用may“可以”表示请求许可，肯定回答用“Certainly”等，否定回答用“mustn’t”表禁止。根据下文“Please read it here”，可知禁止带出阅览室，故选C。

例7．（2021·江苏·扬州中学教育集团树人学校八年级期末）—We ________ keep quiet in the library.

—Yes, I agree with you. And we ________ bring our student cards every time.

A．must; mustn’t B．have to; mustn’t C．must; don’t have to D．have to; mustn’t

【答案】C

【详解】

句意： ——我们必须在图书馆保持安静。——是的。我同意你的看法。我们不需要每次带学生卡。

考查情态动词。must必须；mustn’t不准，禁止；don’t have to不必要；have to不得不，强调客观；根据“We...keep quiet in the library.”及常识可知，在图书馆必须保持安静，且是强调主观意愿上的必须，应用must；结合“bring our student cards every time”可知，没有必要每次都带学生卡，应用don’t have to，故选C。

例8．（2021·青海·海东市教育研究室八年级期末）Li Lei can’t go hiking with us today, because he ________ take care of his sick mother.

A．may B．has to C．mustn’t

【答案】B

【详解】

句意：今天李磊不能和我们去远足了，因为他不得不照顾他生病的母亲。

考查情态动词。may可以；has to不得不；mustn’t禁止；根据“Li Lei can’t go hiking with us today,”可知，不能去远足，应是有必须要做的事情，故选B。

【真题演练】

9．（2021·四川资阳·中考真题）We all need to know ________ to do if there is an earthquake.

A．how B．what C．which D．whether

10．（2021·湖北省直辖县级单位·中考真题）—So many books here! Have you decided ________ to read first?

—Yes. Little Women.

A．how B．which C．when D．where

11．（2021·江苏常州·中考真题）—My family will go on a trip to Beijing this summer, but we haven’t decided ________.

—Why not take the high-speed railway?

A．when to leave B．how to get there C．which hotel to choose D．how long to stay there

12．（2020·江苏宿迁·中考真题）My bike was broken yesterday，so I____walk home．

A．might B．had to C．must D．could

13．（2020·山东青岛·中考真题）—Allen, shall we go to the bookstore this afternoon?   

— I'm sorry, David, but I ________ meet my cousin at the train station.

A．have to B．can C．may D．could

14．（2021·西藏·中考真题）—Have you seen my school ID card, mum? I can’t find it.

—Oh, it ________ be in your bookcase. I saw you put it there last night.

A．can’t B．would C．mustn’t D．must

15．（2021·江苏镇江·中考真题）The sign “No Littering” shows that we ________ throw rubbish in the park.

A．needn’t B．won’t C．mustn’t D．may not

16．（2021·青海西宁·中考真题）Children ________ be told not to swim in the river.

A．can B．must C．may D．might

【过关检测】

17．（2021·黑龙江齐齐哈尔·三模）—Where is Monica?   —She ________ be in the reading room. She loves reading books when she is free.

A．must B．need C．can’t

18．（2021·山东青岛·一模）Children under 12 ________ ride bikes on the road.

A．won’t B．needn’t C．wouldn’t D．mustn’t

19．（2021·贵州六盘水·二模）According to the traffic rules, children under 18 ________ drive cars on the road.

A．can’t B．needn’t C．mustn’t

20．（2021·山东济南·三模）—May I take the newspaper away?

—No, you ________. You can read it only here.

A．needn’t B．shouldn’t C．mustn’t D．couldn’t

21．（2021·黑龙江·哈尔滨市第四十七中学二模）Life is like riding a bicycle. To keep your balance, you ________ keep moving.

A．can B．must C．can’t

22．（2021·广西·平果市教研室二模）We ________ go across the road when the traffic light is red.

A．can’t B．mustn’t C．needn’t D．couldn’t

23．（2021·山东菏泽·二模）—Can you take your mobile phone to class on school days, Li Hua?

—No, I can’t. I ________ follow the school rules.

A．must B．may C．can

24．（2021·湖北·武汉一初慧泉中学模拟预测）Peter, I know you are tired now, but _______ you always run when the pressure gets too much?

A．must B．can C．may D．need

25．（2021·安徽亳州·三模）—Can we walk across the road now, dad?

—No, we _________. We have to wait until the light turns green.

A．couldn’t B．shouldn’t C．needn’t D．mustn’t

26．（2021·江苏淮安·二模）—What makes the children look so tired?

—They didn’t pass the English exam so they ________ do their best to study now.

A．can B．may C．have to D．could

27．（2021·山东·青岛大学附属中学二模）—Mom, ________ I hang out with my friends now?

—Sure, but you ________ clean up your bedroom first.

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

28．（2021·内蒙古·呼和浩特市回民区教育局教科研室二模）Nowadays we ________ order dishes with our mobile phones and ________ wait for waiters to bring the menu in many restaurants. It’s up to you.

A．can; don’t have to B．may; needn’t to

C．must ; needn’t D．may; mustn’t

29．（2021·山东临沂·二模）—Allen, shall we go to the bookstore this afternoon?

—I’m sorry, Jack, but I ________ meet my cousin at the train station.

A．can B．have to C．may

30．（2021·福建泉州·二模）—I can’t give up smoking, doctor. It’s so hard for me!

—For your health, I’m afraid you ________.

A．may B．can C．have to

31．（2021·黑龙江·模拟预测）—Must I finish all the exercises today?       

—No, you ________, but you ________ finish them before Friday.

A．mustn’t, have to B．don’t have to, must C．needn’t, need

32．（2022·江苏无锡·二模）—Sally feels stressed from time to time, but she doesn’t know ________ about it.

—I think she can get help from her teachers or parents.

A．what to talk B．when to talk C．where to talk to D．who to talk to

33．（2022·湖南郴州·一模）My mother always teaches me how ________ water in my daily life. That really helps me develop a good habit of using water.

A．to save B．saving C．saved

34．（2022·河北邯郸·一模）—Hey, Linda. Can you tell me ________ to study for an English test?

—Well, you can work with a study group.

A．how B．when C．why D．where

35．（2022·福建三明·二模）—Could you please tell me ________ to Shanghai for traveling?

—It’s hard to say, maybe, next week.

A．how to get B．when to go C．what to take

36．（2022·黑龙江·哈尔滨市风华中学校模拟预测）When you don’t know ________next, you can ask your parents for help. They are sure to give you a hand.

A．what should you do B．how to do C．what to do

37．（2022·江苏南京·模拟预测）— I can’t decide _________ to do with so many old clothes.

— Why not send them to a charity?

A．which B．what C．how D．where

38．（2022·安徽滁州·一模）—Joe, do you play basketball?

—No, I don’t play any sports. But I know ________ to play chess.

A．when B．how C．where D．why