资源简介

(共21张PPT)
UNIT 2 Let’s celebrate!
Using language
Learning Objectives
To know the usage of the modal verbs: can, could,may, might,must+v原
To know the usages of the modal verbs:can, could, may, might, must be doing
To know the usage of the modal verbs:can, could, may,might, must+ have done
情态动词(2)
自主探索
观察以下教材原句并思考黑体部分的功能。
1．As parents, they try to keep that magic alive for their children for as long as they can.
2．Who could it be from
3．The children must have been very excited as they opened it.
4．Interestingly, the letters did not contain the usual warnings to children that they might not receive their presents if they were not good.
5．By expressing love for his children in such a special way, Tolkien may indeed have been the real Father Christmas.
[归纳填空]　
can
could; might
must have been; may have been
（1）. 表示能力：can表示现在的能力，could(can的过去式）表示过去的能力。
She can swim very fast.
When I was young, I couldn’t play basketball.
（2）. 表示请求和许可：could表示更委婉的语气，回答时只能用can。
—Could I borrow your pen → 礼貌请求
—Yes, you can.
can和could
(3)表示推测，意为“可能”。多用于否定句或疑问句,could比can可能性更小。
注意：表示推测、许可时，could不代表过去，could 和can 没有时间上的差别。
—Can he be in the reading room now
—No, he can't be in it. Because I saw him in the office just now.
——他现在可能在阅览室吗？
——不，他不可能在(阅览室)。因为我刚刚在办公室看见他了。(现在)
It's so late. They can't be reading in the library.
这么晚了，他们不可能在图书馆里看书。(此刻)
He can't have gone to Shanghai for I saw him a minute ago.
他不可能去了上海，因为我刚才还看到他了。(过去)
(4)表示理论上或习惯上的可能性，意为“可能会”。
Smoking can be harmful to the health.
吸烟有害健康。
即学即练1 选出下列句中can/could的含义
A.表示能力` B.表示推测
C.表示请求和许可 D.表示理论或习惯上的可能性
①In my opinion, he can't be so rude.________
②I can speak English fluently while he can't.________
③Scotland can be very warm in September.________
④—Could you please clean this room
—Yes, I can.________
B
D
A
C
(1)表示征求对方的许可或允许(不用might)对方做某事。
—May I come in
—Yes, you may/can.(No, you can't.)
——我可以进来吗？
——是的，你可以进来。(不行，你不能进来)。
You may go now.你现在可以走了。
may和might
(2)表示推测(把握不大)，意为“可能”，多用于肯定句。might比may可能性更小。
Today is Sunday. She may not be in the office.
今天是周日。她可能不在办公室。(现在)
They might be holding a meeting in the classroom.
他们或许正在教室开会。(此刻)
—What has happened to George
—I don't know. He may have got lost.
——乔治发生了什么事？
——我不知道。他可能迷路了。(过去)
(3)may用于祈使句，表示祝愿。
May you have a long and fruitful marriage.
祝你们婚姻长久美满。
(4)“may/might as well＋动词原形”表示“不妨，不如”。
I may/might as well start at once.
我还不如马上就动身。
即学即练2 选出下列句中may/might的含义
A.表示许可　B．表示推测　C．表示祝愿
①She was worried that we might get hurt.________
②May you good luck！________
③May I watch TV now？________
B
C
A
(1)must表示命令或强烈的建议，意为“必须”。mustn't表“禁止”“不准”。
All the students must obey the school rules.
所有学生必须遵守校规。
You mustn't stop your car in the busy street.
你不可以把车停在繁忙的路上。
must
(2)表示有把握的肯定推测，只能用在肯定句中，意为“一定；准是”；在否定句、疑问句中要用can't代替。
He can’t have left already—his bag is still here.他不可能已经离开了，他的包还在这儿。
You didn’t have breakfast today. You must be very hungry now.
你没有吃早餐。你现在一定饿了。（现在）
Look! All the students are in the classroom. They must be having class now.
看，所有的学生都在教室里。他们一定正在上课。(此刻)
The playground is wet this morning. It must have rained yesterday.
地面是湿的，昨天晚上一定下过雨。(过去)
(3)表示说话人的一种态度，意为“偏要；硬要；偏偏”。
Why must he go out in the bad weather
为什么他偏要在这种坏天气出门？
名师点拨　以must开头的一般疑问句的肯定回答中要用must，否定回答中要用needn't/don't have to。
—Must I finish my homework before eight o'clock
—Yes, you must./No, you needn't/don't have to.
——我必须要在8点之前完成作业吗？
——是的，必须。/不，没必要。
即学即练3 选出下列句中must/mustn't的含义
A．表示“必须” B．表示“一定；准是”
C．表示“偏要；硬要；偏偏” D．表示“禁止，不许，不准”
①You mustn't fire without my signal._______
②Why must you always find fault with others？________
③You must be hungry after all that walking.________
④You must practice your spoken English if you want to improve.________
D
C
B
A
Homework
Review the usages of modal verbs in this class.
Finish the exercises on page22.

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