课程内容

《Festivals around the world （Part 4）》
情态动词的特点
情态动词有一定的意义
无人称和数的变化
通常不带to,后接动词原形
表示说话人的语气或情绪
can/aould
1.can 表示能力（ability)
1)Man can't live without air.
2)A computer can't think for itself;it must be told what to do.
3)I'm starving to death.I can eat two bowls of rice now.
表示过去有能力并且成功地做了某事不用could,而用was/were able to
was/were able to=managed to do=succeeded in doing
The fire spread through the house quickly but everyone was able to get out.=...managed to get out =...succeeded in getting out.
2.表示可能性（possibility):可能
1）表示“偶尔的可能”，肯定句
*She can be really stubborn at times.
*It can be pretty cold here,even in spring.
2)“理论上的可能”、“客观上的可能”，不是说话者主观认为可能，否定can't
*He hasn't eaten for hours.He can be hungry.
*One of the few things you can say about English people with certainty is that they talk a lot about the weather.
3.表示许可（permission,request)
*Can/Could I borrow your car?
Yes,you can./No,you can't.
*You can/can't use my dictionary.
2)could 的主要用法是：
A could 是can 的过去式，表示与过去有关的能力和推测：
eg.We all knew that the young man couldn't be a doctor.
B could 可以代替can 表示请求，但语气较can客气、委婉：
eg:Could you lend me your dictionary?
Could I use your bike?
3)can 和could 接动词的完成形式，表示可能已经做某事。can 用在否定和疑问句中，表示不相信、怀疑等态度。
eg.They can't have gone out because the light is still on.
Exercides:
1.How is"can/could"being used in the situations?
1)Two eyes can see more than one.
2)A cracked bell can never sound well.
3)Children can be very trying.
4)This sort of thing can't go on!
5)The money has disappeared.
Who could/can have taken it?
May/might
1.表示允许permission
1)Dogs may not be taken into the museum.
2)You may take either of the two.
3)You may do exactly as you like.
*May/might I...?
1)Yes,you may./Of course./Yes,please do.
2)No,please don't./No,you may not./I'd rather you didn't./I'm afraid not.
2.表示可能性，推测；可能
1）对现在的推测：may/might+动原，多用于肯、否句
*He may be busy now.
*It may be a new species.
2)对现在进行推测：
may/might be doing
*They may be wanting to know when I arrive.
*He might be working in the office.
3)对过去的推测
may/might have done
*He looks unhappy.He(may/might have failed)in the exam.(faid)
*I was careful not to look at him.He (may/might have seen)the surprise in my face.(seen)
3.might have done"本来可能做却没做...“不可以用may
1)He might have given you more help,even though he was very busy.
2)You shouldn't have awum in that river.You (might have been eaten)by fish.(eat)
3)You (might have been)him help,though you were busy.(give)
4.表示祝愿：may 不可以换为might,并且谓语动词永远用原形。
1）May you be happy!
2)May you have a long and happy life.
3)May there never be another world war.
4)May God bless you.
5)May all your dreams come true.
Shall
1.用于第一人称（单纯的将来，美，will):将要，会
1）I shall be very happy to see you again.
2)By the end of this year.I shall have been working here for 20 years.
2.用于一、三人称（征求对方建议：第二人称用will)：...好吗？要不要...？
1）Shall she come to help you?
2)Shall thouse goods be sent to you?
*Will you please go to the museum with me?
3.二、三人称陈述句（表说话者的意图intention,允许permission,告诫warning,威胁threat,命令order,决心determination ,预言prediction,承诺promise 等）一定会，应该，可以要，给得
1)It shall be done as you wish.
2)They shall suffer for this;they shall pay what they have done.
3)He shall do as I order.
4)If you work well,you shall have higher wages.
5)If you won't do as I tell you,you shan't go to the party.
6)Heaven and earth shall pass away,but not my word.
7)He is determined that you shall succeed.
4.二三人称陈述句（表强烈意志和不可避免性）一定
1.We shall defend the island,强烈意志 whatever the cost may be.
2.We shall have to be ready.强烈意志
5.第三人称（在条约、规章、法令等文件中表义务或规定）必须，应
1）Persons under 18 shall not be employed in night work.
2)The new regulation shal take effect on June 1st.
3)Each party shall respect the conditions of this contract.
4)Candidates shall remain in their seats until all the papers have their collected.
Should,ought to
1.(shall 的过去式）将
1).We thought that we should never see you again.
2)We hoped that we should have confidence in each other again.
3)The weather report said that we should have rain tonight.
2.(表示义务、责任、劝告、建议）应该
* should have done （含责备之意）本应该做却没有做
1）Children should be devoted to their parents.
2)You shouldn't be so careless.
3)I think you should get touch with your lawyer.
4)You should have told me the news earliers,but you didn't.
3.(表可能性、推测）应该、可能
1）The report is written after careful invertigation,so it should be reliable.
2)They should have arrived in Beijing by this time.
4.万一（表语气较强的假设，用于if引导的条件从句中）
1）If he (should)fail to come,ask Jack to work in his place,
2)Should it rain tomorrow the meeting would be postponed.
2.虚拟语气
insist,urge,demand,decide,request,require,order,command,advise,prefer,propose,suggest
1)我向他建议我立刻走。
I suggested to him that I (should)go at once.
2)我们决定马上开始大扫除。
It was decided that we (should) start a clear-up st once.
must,have to
must 主观    have to 客观
1.表示必要性（necessity):一定要，必须
1）You must have a passport if you want to travel abroad.
2)We must think about this very seriously.
2.表示说话者的命令或强烈劝告。
You must stop smoking and drinking.
1)mustn't “禁止”
You mustn't smoke here.
2)Must I clean all the windows?
Yes,you must,
No,you needn't./No, you don't have to.
3.must表示肯定的推测，否定：can't
1)must do (对现在情况推测）
→can't do
He must be in the classroom now.
2)must be doing→can't be doing
He must be sleeping,isn't he?
He can't be playing football.
3)must have done(对过去情况推测）
→can't have done
You're on time.You must have got up early this moring.
The husband thought his wife must have been looking forward to his return.
4)表示推测的must 只用于肯定句
疑：can,否：can't'
--Can it be the headmaster?
--No,it can't be the head master.He has gone to Shanghai.