人教版（新课程标准）必修三Unit 2 Healthy Eating情态动词课件（25张PPT）

(共25张PPT)
Unit 2 Healthy Eating
Modal Verbs 2
Teaching aims
To learn some modal verbs: ought to, have to, mustn’t and needn’t;
To finish some exercises using modal verbs.
Review
What modal verbs have you learned in Unit 1
情态动词的用法:
情态动词没有__________的变化，情态动词第三人称单数不加-s。
情态动词不能单独使用，情态动词后跟动词______。
人称和数
原形
情态动词的特殊用法:
can’t help doing sth.
can’t too…
may/might as well
May you…
1. Excuse me, ______ you tell me the way to the railway station, please
could
Test
小组抢答
can/ could
2. ______ you like a cup of coffee
Would
could/ would
3. That is an important book.
You ______ keep it well.
must
may/ must
4.The restaurant ______ be very good. It’s always full of people.
must
must/ would
5. You look tired. You _______ go to bed now.
should
can/ should
6. In China, many children ________ wear uniform when they go to school.
have to
should/ have to
7. Peter _____ come with us tonight, but he isn’t very sure yet.
may
may/ will
How many points have you got
Today we are going to learn more about modal verbs!
观看微视频 自主学习
1. must表示一种____观的需要，而have to表示一种____观的需要，意思是 “不得不”。
I ________ attend an important meeting this afternoon.
今天下午我不得不参加一个重要的会议。
2. have to
have to 的第三人称单数形式是：________
have to 的过去式：________
must / have to
要点归纳
主
客
have to
has to
had to
must 用在否定句中
mustn’t 只有一个意思，禁止
You mustn’t use cellphone in classroom.
You mustn’t go out at night.
should 和ought to 都为“应该”的意思，可用于各种人称。ought to 的语气稍重一些,表示____观要求 ,而should 表示___观要求。
You ought to (should) follow your teacher’s advice.
ought to／should
ought to否定形式为：____________
客
主
ought not to
1. need to do sth 需要做某事(实义动词)
need do sth 有必要做某事(情态动词)
I need to get up before 6 o’clock.
Need I finish my homework today
-- No, you needn’t.
need / don’t have to
need 提问：
--Need I finish the work today
--Yes, ________________.
No, ________________________.
you must
you needn’t/ don’t have to
you must
must 提问：
--Must we do it now
--Yes , ________________.
No, you _____________________.
needn’t/ don’t have to
回答must 提问时，否定用needn’t 或don’t have to.
要点扩展
should have done 本该做…却未做
shouldn’t have done 本不应该…做却做了
--I couldn’t sleep last night.
--You should have counted sheep.
--I did. But I made a mistake and it took me all night to correct it.
needn’t have done 本不必做……
You needn’t have driven your car to school. It’s only 5 minutes walk.
must have done 肯定做过……
Mr. Green can’t find his wallet. He must have dropped it in the supermarket.
一、请用适当的情态动词填空。
1. I’ll _________ look after my sister at home this Sunday.
2. You _________ go outside to play as it is snowing heavily.
3. I got up late this morning, so I _______ take a taxi to school.
4. It _______ have rained last night, for the ground is wet.
Practice
have to
mustn’t
had to
must
have to/ ought to/ must/ mustn’t/ need
二、翻译下列句子：
明天我必须去医院看我朋友。
你应该比以前更努力。
一切都会好的，你不必担心它。
他肯定去过北京了。
你能给我一些怎样学好英语的建议吗？
Keys:
I must (have to) go and see my friend in hospital tomorrow.
You should (ought to) work harder than before.
Everything will be ok. You needn’t worry about it.
He must have been to Beijing.
Could you give me some advice on how to learn English well
Homework
Finish the exercise on the paper.
Remember the key points learnt today.