Modal Verbs (必修3，Unit1)

课件23张PPT。情态动词用法·情态动词的语法特征1）?情态动词?不能单独做谓语，除ought ?和have?外，
后面只能接不带to?的不定式。 2）?情态动词没有人称，数的变化，但有些情态动
词，如can、will也有一般式和过去式的变化。3）?情态动词的“时态”形式并不是时间区别的主要标
志，不少情况下，情态动词的现在式形式和过去
式形式都可用来表示现在时间、过去时间和将来
时间。will和would： 1. would 表示过去的习惯性
One day a week he _____spend a whole day in silence.would2.will和would表示意愿、意志，可用于各种人称If you _____help me with my English, I _____ be very happy.
I promised that I _______do my best.willwillwouldused to 3. 在疑问句中用于第二人称，提出请求或询问。_____you tell her that I'm here?
If you want help - let me know, ____you?
_____you type this, please?
_____ you sit down?
_______you help us, please? would比will客气委婉WillwillWillWon'tWouldcan 和could：_______ you offer me some kind of job?
_______ I help you?
_______ you ride a bike?
_______ he be at home?
How _______ you say that?
I _______ say that he has finished his work.Can/CouldCanCanCan/Couldcouldcan’t1请求、允许 2 主动提供帮助 3能力
4 可能性 5 责备 6 预言、预测can 和could：can, could 表能力和be able to的区别She can/is able to sing the song in English.
This machine can make you feel comfortable.1 can的主语是人或物,be able to的主语是人 We’ll be able to finish the work soon.
I haven’t been able to see the film.2 can只用于现在式和过去式(could
be?able?to可以用于各种时态。 3 be able to 表做成了某事may 和might ：1.表示说话人的猜测/可能性:通常只用于肯定句和否定句中。---_____I use your pencil?---Yes, you_____./ No, you________.2. may和might 用于一般问句中表示委婉的请求,肯定回答用may,否定用mustn’tMaymaymustn’t3. 表示祝愿;但语气较正式:
May you succeed!
May you have a good journey!May +sb.+ do! shall和should：should表示义务、建议、劝告，意为 “应该”。
“should+ have+过去分词”表本应该在过去做但没做。You should keep your promise.
She should have passed the exam. _____I open the window for you？（征求意见）
_____he fetch some water for you？（请求）2.在疑问句中,用于第一、三人称，用来表示请求或征求意见。ShallShall shall和should：You shall do as I say.
Tell him that he shall have the book tomorrow.
Nothing shall stop me doing it. 3. shall用于第二、三人称表示允诺、警告、命令、决心等。must 的主要用法： We must all die.
You must get up early.
He must be crazy.
1. 表示必然性。2. 表示强制或者义务。
3. 表示推测，语气非
常肯定，近乎确定的
意味，一般用在肯定句。 注意: 1 must not 的意思是不许可，不应该或者禁止。
We mustn’t waste our time.  ---- May I take this magazine out? ---- No, you mustn’t.
2 must 用于一般疑问句的时候，肯定回答应该用yes, please 或者 I’m afraid so, 其否定回答应该用 needn’t 或者 don’t have to。如：·归纳：表可能、猜测2）?can一般用于疑问句、有把握的否定推测
may/might用于没有把握的肯定、否定推测
must用于有确切把握的肯定句3）?对现在、未来推测：…+ do
对过去推测：…+ have done
对此刻正在发生的事情推测: … + be doing4 ) should (大概、按理应当) ; will(很可能、准会) 也可表推测，一般只用于肯定句 2. A: ______ Xiao Feng find the origin of Easter from that book?
B: No, he _____________. 1. A: ______ you like to go to a special event with us on Saturday?
B: Yes, I _____________________ _________.Would’d like to go with you on SaturdayCouldcouldn’t find itExercise 3. A: _____ I go with my friend to the harvest festival?
B: Yes, you _________________ ________. 4. A: If I want to be a doctor _______ I study science?
B: Yes, you __________________. should study scienceMay may go ( with your shouldfriends )5. A: He is very handsome. ____ he play the role of the prince?
B: No, he _______________________ ______. can’t play the role of theCanprince 6. A: The neighbour’ s children are older this year. _______________ they stop playing tricks at Halloween?
B: Perhaps, they __________ ________________________.
__________________________
____________.Mightor Shouldmight stopor should stop playing tricksplaying tricks at Halloweenat Halloween ----____ I go out to play, mum?
----No, you___. You should do your
homework first.
A. Might; wouldn’t
B. May; had better not
C. Must; mustn’t
D. Need; mustn’tBPractice 2. ---Where is Emma?
---I can’t say for sure where she is,
but she___ be out shopping.
A. can
B. should
C. must
D. mayD3. The room is in a terrible mess; it
____ cleaned.
A. can’t have been
B. couldn’t be
C. may have been
D. would be
A4. How ____ you say that you really
understand the whole story if you
have covered only part of the article?
A. can
B. must
C. need
D. mayA5. There ____ be any difficulty about
passing the road test since you have
practised a lot in the driving school.
A. mustn’t
B. shan’t
C. shouldn’t
D. needn’t
CExercise I．单句改错
1. Mr. Smith looks pale. He can be ill.
2. When we worked in the same office, we will
often have coffee together.
3. You must be joking. That mustn’t be true.
4. Come to take the photos tomorrow morning.
It may be ready by then.
5. The fire spread so fast that only one-third
of the people could escape the fire.maywouldcan’tshouldwere able toII．用正确的情态动词填空。
1.?When we are cooking with a gas fire, we
__________ (can/must) keep the window open.
2.?Mr. Joseph has stayed in the US for several
years. He __________ (may/can) speak
English quite well.
3.?No one __________ (will/would) think of
wearing a long coat in summer.
4.? It __________ (can’t/mustn’t) be Miss Gao. I
know she has gone to Beijing.
5.? You say you __________ not do it but I say
you __________ (shall/will).
mustcanwouldcan’twillshall