Unit 5 My Future Lesson 28 Rich or Poor It Doesn't Matter! 课件(共35张PPT)

(共36张PPT)
情态动词
　
情态动词
表示推测
不表示推测
can could
may might
shall should
must
will would
ought to
have to
dare (daren’t)
need (needn’t)
used to
情态动词有一定的意义，但没有人称和数的变化，不能独立使用，它和后面的动词构成谓语．
只作情态动词的 can/could, may/might, 　　　　　　　 　ought to， must
可情态可实义的　need, dare/dared
可情态可助动词的 shall/should, will/would
相当于情态动词的 have to, used to
must , can/could, may/might 的用法
must
1.must 表示推测时， 只能用于肯定句。
e.g.这个电脑肯定出了问题。
There must be something wrong with the computer.
你努力学了一整天， 一定累了吧
You have worked hard all day. You must be tired.
must , can/could, may/might 的用法
注意：must用于肯定句中可表示“偏偏”。
Naturally, after I told her what to do, my daughter must go and do the opposite.
自然地，在我交代女儿做什么之后，她偏偏要做相反的事情.
2.must +be doing/do 表示对现在的动作进行肯定推测
e.g.他现在一定在看小说.
He must be reading novels now.
他们买了一辆新车。 他们一定很有钱.
They have bought a new car. They must have a lot of money.
3.must +have done 表示对过去发生的事情作出的肯定判断
e.g.他们在玩篮球， 他们一定完成了作业。
They are playing basketball, they must have finished their homework.
路是湿的。昨天晚上一定下雨了。
The road is wet. It must have rained last night.
对现在或将来情况推测：must +动词原形。
must只能用于肯定。否定和疑问分别用can’t和can。
e.g. He must tell a lie.
Can he tell a lie
He can’t tell a lie.
*must-should/ought to –may-might/could+do
可能性依次减弱
(对过去情况推测：must may, might)+完成时。
e.g. You must have met him before.
must—may—might可能性依次减弱
must只能用于肯定句，译成“一定”。否定和疑问分别用can’t / couldn’t和can / could。
e.g. Could /Can it have happened last night
It couldn’t/can’t have happened last night.
He must be reading, isn’t he
You must do it yourself, don’t you
He must have gone over the article, hasn’t he
It must have rained last night, didn’t it
表猜测语气的反意疑问句的构成
can, could 和be able to的用法
e.g. She can/be able to sing the song in English.
This machine can make you feel comfortable.
1.can, be able to都可表示“能力”
can的主语是人或物,be able to的主语是人
can, could 和be able to的用法
e.g. We’ll be able to finish the work soon.
I haven’t been able to see the film.
2.can只用于现在时和过去时(could)。be able to可以用于各种时态。
could用于表示泛指过去的能力。 e.g. I could read when I was four.
Although the soldier was badly wounded, he was able to tell what had happened.
3.表示特定的某一过去能力或表示成功地做了某事时，只能用was/were able to， 不能用could。
e.g. He was able to escape from Europe before
the war broke out.
He was able to swim before he got tired. 　　
表示过去的能力
can/could
1. can /could 表示推测时，只能用在否定句或疑问句中。
e.g. It’s so late. Can Tom be reading
Can it be Mr. Green
这个人不可能是玛丽， 她生病了。
It can’t be Mary. She has fallen ill.
她不可能在说谎。
She couldn’t be telling lies.
在疑问句中 could 比can 更有礼貌，在此不是can的过去式。
e.g. Can you wait a moment please
Liz, can you do me a favor
Excuse me, could you tell me the way to
the station
I wonder if you could help me. (请求)
2. can/could have done 对过去发生行为的可能性进行推测:
刚才我还看见他了， 所以他不可能出国的。
I saw him just now so he couldn’t have gone abroad.
门是锁着的， 所以她不可能在家。
The door was locked.
She couldn’t have been at home.
3. can/could have done “本可以，本来可能已经”用于肯定句中，表示对过去发生的事情做出的判断.
e.g.你本来可以考的更好。
You could have had a better mark.
may/might
1.may/might表示推测时，只能用于陈述句，表示对现在或将来要发生的动作把握不大。
e.g.她们明天可能会到这里来。
They may come here tomorrow.
他们可能还在等我们呢。
They may be still waiting for us.
2.might 可用于指过去的行为或者表示可能性更小。
e.g.他也许在做功课吧。
He might be doing his homework now.
我问他我是否可以离开。
I asked him if I might leave.
I asked him “May I leave now ”
3.might/may have done,表示对过去发生的动作进行可能性推测。
e.g.他可能去医务室了。
He may have gone to the clinic.
他可能已经从报纸上知道这个消息了。
He might have read about the news in the newspaper.
4、may 表示许可，表示允许别人做某事， 也可征求对方的许可。
May I open the door
We may keep the book for two weeks.
5、用于祈使句，表示祝愿。
May you succeed!
May you have a nice trip!
表示推测——情态动词的重要用法.
肯定的推测
可能的推测
否定的推测
疑问的推测
must
对将来 对现在 对过去
情态动词
may, might
can’t,
couldn’t
can, could
+ V. + V. + have done
常见must be + be doing
+ V. + V. + have done
+ be doing
可以用not表示“可能不”
+V. + V. + have done
+ be doing
+ V. + V. + have done
+ be doing
Will /Would you do… (表请求would 更委婉)表意志，愿望，决心
would表过去反复发生的动作或某种倾向
“总是,总要”
used to表过去常常（现在已没有这种习惯）
“过去常常”
used to 可于状态动词连用　would不可以
e.g. He used to be a quiet boy. (　　)
He would be a quiet boy. (　　 )
√
×
will/would
shall/should
1.shall 用于第二、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。
e.g.1)You shall go with me.(命令)
2)You shall have the book when I finish it.(允诺)
3)He shall be punished.(威胁)
2. shall用于第一、三人称疑问句中，表示说话人征求对方的意见和向对方请示。
e.g.4)Shall we begin our class （征求意见）
5)When shall Mike be able to leave hospital (请示)
3.用于条约，规定，规章等文件中，表示一种义务，多用于第三人称中。
6) “The interest ___be divided into five parts, according to the agreement made by both sides.” declared the judge.
A. may B. should C. must D. shall
用于表达合理推断。
e.g. It is three o’clock, the football game should begin now.
Mary took dancing lessons for years, she should be an excellent dancer.
2. should 的用法
2. should 的用法
注意：should可表示“居然，竟然”。
e.g.我不敢相信这样一个绅士居然对老人如此无礼。
I can’t believe such a gentleman should be so rude to the old.
e.g. Young people should learn how to use computers.
Every citizen ought to obey law.
You ought not to go.
3. should常表示劝告、建议、命令，与ought to意义相近，但ought to多表示责任、义务，语气强烈。在疑问句中通常用should代替ought to。
e.g. You should/ought to have told her the truth earlier.
She shouldn’t have left without saying a word.
4.should/ought to have done表示责备或批评,意为“本应该做到…但没有做到…”,用于否定则表示“本不该…但”ought to的语气更强烈.
must 和have to
1.must用于一般问句中,肯定回答用must否定式用 needn’t或don’t have to，做 “不必”,mustn’t表示“禁止，不允许”
e.g.— Must I finish all assignments at a time
—Yes, you must.
No, you needn't.
You mustn’t get off while the car is still moving.
e.g. I don’t like this TV set. We must buy a new one.
There was no more bus. They had to walk home.
2.表示“必须”这个意思时，must 和have to 稍有区别。must着重说明主观看法，have to 强调客观需要。另外，have to 能用于更多时态。
need /dare
a. need 表需要和必须常用于否定句和疑问句,needn’t have done “本不必做... ...”
b. dare 表敢,常用于否定句,疑问句和条件句中。
c. dare与need 用做实意动词时有时态，人称和数的变化,但dare用于否定句和疑问句时常接不带to的不定式,need后要接带to的不定式。
1. I don't know where she is, she _______ be in
Wuhan.
2. At this moment, our teacher ________________
our exam papers.
这时，我们老师想必在批改试卷。
3. The road is wet. It ________________ last night.(rain)
4. Your mother ______________________ for you.
　你妈妈一定一直在找你。
may
must be marking
must have rained
must have been looking
5. Philip ________________________ seriously in
the car accident. 菲利普可能在车祸中受了重伤.
6. ---Linda has gone to work, but her bicycle is
still here.
　---She _____________________ (go) by bus.
7. Mike ________________ his car, for he came to
work by bus this morning.
　迈克一定还没有找回他的车，因为早上他是坐
公共汽车来上班的。
may (might) have been hurt
may (might) have gone
can’t have found
Thank you！