【】“情态动词＋have done”结构的用法。
【热点突破】
1．can和could的用法
(1)表示“能力”。
(2)表示理论上的可能性，“有时候可能会”，用于肯定
句中。
(3)表示礼貌地请求，意为“能，可以”。could可代替can,表示委婉的语气。
(4)cannot...too/enough表示“无论……也不过分”；“越……越好……”。
No one can be compared with Yao Ming in playing basketball.在打篮球方面，无人能与姚明相媲美。
It is usually warm in my hometown in March，but it can be
rather cold sometimes.
我的家乡三月份通常很暖和，但有时候也会相当冷。
You can’t be too careful while driving.
开车时越小心越好。
—Could I use your bike tomorrow?
——明天我可以用一下你的自行车吗？
—Yesyou can./No，I’m afraid not.
——是的，你可以。/2．may和might的用法
(1)表示允许、许可、请求，might比may的语气更委婉。
当may用于疑问句时，其否定回答：No，...mustn’t。
(2)may as well＋动词原形“最好；倒不如……”。
—May I take this book out of the reading room?
——我可以把书拿出阅览室吗？
—Noyou mustn’t.You read it in here.
——不，绝不可以。你在这儿读。
If you think the price of beef is too highyou may as well buy some pork.It depends on you.如果你认为牛肉太贵的话，你不妨买些猪肉。这由你自己决定。
3．must的用法
(1)表示必要性，意为“必须”。当must用于疑问句时，其否定回答为：No，...needn’t/don’t have to。
(2)表示偏执，固执，意为“非得，偏要”。
—Must you interrupt now? Can’t you see I’m on the phone？——你一定要现在插话吗？难道你没有看到 我 正 在打电话吗？
—Sorry sir，but it’s urgent.
——抱歉，先生。但事情紧急。
You mustn’t park hereIt’s an emergency exit.
你不可以在这儿停车！这是紧急出口处。
—Must I give up smoking？——我必须戒烟吗？
—Yes，you must./No，you needn’t.
——是的，你必须。/
4．shall的用法
(1)用于第一、第三人称疑问句中，表示说话人征求对方的意见或向对方请示。
(2)用于第二、第三人称陈述句中，表示说话人 给对 方 的 命令、警告、允诺或威胁。
—Will you read me a story，Mummy?
——妈妈，给我讲个故事好吗？
—OK.You shall have one if you go to bed as soon as possible.——好的，如果你尽快上床睡觉我就给你讲一个。
—What time shall I pick you up at your house tomorrow，sir？
——先生，我明天什么时候到你家接你？
—I haven’t decided on the time.But I will call you.
——我还没有决定时间，但是我会给你打电话的。
5should 的用法
(1)表示劝告和建议，意为“应该”。
(2)表示推测、可能性、预期，意为“应该；可能”。
(3)用于表示感情或意志等的that从句中，意为“竟然……；居然……”。
There shouldn’t be any difficulty about passing the road test since you have practiced a lot in the driving school.
既然你在驾校训练了那么多，通过路考应该没有什么困难。
I should
go and visit him this afternoon，but I wonder if I will be free.
今天下午我应该去看望他，但是我不知道我是否有空。
It seems unfair that this should happen to me.
真不公平，这件事竟然发生在我身上。
6．will和would的用法
(1)表示意志或意愿。will指现在，would指过去。
(2)表示习惯性动作,意为“总是”,will指现在,would指过去.
(3)表示功能，意为“能，行”。
The door wouldn’t open，no matter how hard she pushed.
无论她怎么努力去推，这扇门就是打不开。
Days later，my brother called to say he was all right，but
wouldn’t say where he was.几天后，我哥哥打电话说他一切
都好，但不愿意说他在哪儿。
Every morning he will have a walk along this river.
每天早晨，他总是沿着这条小河散步。
例1．(2015·高考北京卷，T29)—Can’t you stay a little longer?
—It’s getting late.I really ________ go now.My daughter is home alone.
A．may
B．can
C．must
D．dare
【变式探究】
Although you ________find bargains in London，it’s not generally a cheap place to shop.
A．should
B．need
C．must
D．can
【热点突破】
情态动词表示推测三步判断：(1)首先看是肯定句、否定句还是疑问句。肯定句中一般must/may/might；否定句和疑问句中一般用can/could。(2)然后看是对什么时间的推测；表示对现在的推测用“情态动词＋do”，表示对过去的推测用 “情态动词＋have done”。(3)最后看句子语气的肯定程度,must(十分肯定)>may(不太肯定)>could/might(可能性较小)。
例2．(2015·高考陕西卷，T21)You ________ feel all the training a waste of time，but I’m a hundred percent sure later you’ll be grateful you did it.
A．should
B．need
C．shall
D．may
【易错警示】情态动词表示推测的误must，may，might，can和could的用法上。要切记：对现在和将来的推测用“情态动词＋动词原形”；对正在发生的动作的推测用“情态动词＋be doing”；对过去的推测用“情态动词＋have done”。
Life is unpredictableeven the poorest might become the richest.
生活是不可预料的，甚至最贫穷的可能变成最富有的。
—Look! There comes our head teacher.
——看！我们班主任来了。
—That can’t be him.He is in Indonesia.
——那一定不是他。他现在在印尼。
【变式探究】
—Has Peter started out？He said he would go hiking with us.
—He________．He is a man of his word.
A．could have started
B．must have started
C．could start
D．must start
【热点突破】have done
例3．(2015·高考天津卷，T7)I ________ have worried before I came to the new school，for my classmates here are very friendly to me.
A．mightn’t
B．mustn’t
C．needn’t
D．couldn’ t
【变式探究】
—Why are your eyes so red? You ________ have slept well last night.
—Yeah，I stayed up late writing a report.
A．can’t
B．mustn’t
C．needn’t
D．won’t
【热点突破】(2015·高考北京卷，T34)If I ________ it with my own eyes，I wouldn’t have believed it.
A．didn’t see
B．weren’t seeing
C．wouldn’t see
D．hadn’t seen
【变式探究】________no modern telecommunications，we would have to wait for weeks to get news from around the world.
A．Were there
B．Had there been
C．If there are
D．If there have been
【热点突破】
例5．(2015·高考陕西卷，T23)Ellen is a fantastic dancer.I wish I ________ as well as her.
A．dance
B．will dance
C．had danced
D．danced
【变式探究】Don’t handle the vase as if it ______ made of steel.
A．is
B．were
C．has been
D．had been
【易错警示】当suggest作“暗示表明”作“坚持认为”时从句要用陈述语气。他的沉默表明他同意我的决定。他坚持说他没有偷过钱。
1.(2015·北京)—Can't you stay a little longer?
—It's getting late.I really
go now.My daughter is home alone.
2.(2015·浙江)It was so noisy that we
not hear ourselves speak.
3.(2015·重庆)You
be Carol.You haven't changed a bit after all these years.
4.(2015·陕西)You
feel all the training a waste of time，but I'm a hundred percent sure later you'll be grateful you did it.
5.(2015·四川)You
be careful with the camera.It costs!
6.(2015·福建)—Sorry, Mum! I failed the job interview again.
—Oh, it's too bad.You
have made full preparations.
7.(2015·天津)I
have worried before I came to the new school, for my classmates here are very friendly to me.
8.(2015·北京34)If I
(see)it with my own eyes, I wouldn't have believed it.
9.(2015·重庆)Without his wartime experiences, Hemingway
(write)his famous novel A Farewell to Arms.
10.(2015·陕西)Ellen is a fantastic dancer.I wish I
(dance)as well as her.
11.(2015·天津)I wish I
(be)at my sister's wedding last Tuesday, but I was on a business trip in New York then.
12.(2015·安徽)It is lucky we booked a room, or we
(have)nowhere to stay now.