1、情态动词和过去将来时一、情态动词情态动词表示说话人对某一动作或状态的态度。初中阶段大家已经学习了一些情态动词，这里将对情态动词的特征、功能和用法进行总结。观察例句1Oliver believes that with a millionpound bank note a man could live a month in London.2Young man，would you step inside a moment，please?3May we ask what youre doing in this country and what your plans are?4I cant say th
2、at I have any plans.5Anyway，I didnt dare to try again.6You mustnt worry about that.7If youll excuse me，I ought to be on my way.归纳用法1情态动词的基本特征(1)在形式上，情态动词没有实义动词的各种变化，只有could，would，had to，might等几个过去式，其他情态动词如must，ought to等的过去式皆与现在式同形。(2)在意义上，大多数情态动词有多个意义，如can可以表达“能力”“可能”“许可”等。(3)在用法上，情态动词与助动词一样，需后接动词原形
3、，构成谓语动词。2情态动词的否定式及缩略形式情态动词否定式缩略形式情态动词否定式缩略形式cancannot/can notcantshallshall notshantcouldcould notcouldntshouldshould notshouldntmaymay not/willwill notwontmightmightnotmightntwouldwould notwouldntmustmust notmustntneedneed notneedntdaredare notdarentought toought not tooughtnt to3.情态动词的主要表意功能用法例句表示
4、能力The little boy can read and write.I could feel the ground shaking.表示可能和推测Those of you who are familiar with the game will know this.They made a bet which would settle their argument.Oh，you must be Sylvias husband.It may seem lucky to you but not to me.That might not be true.There ought to be enoug
5、h space for all of us.表示不可能It cant be Mary，she is in New York now.表示许可或禁止You can go off duty now.You cant open it until two oclock.You may not smoke here.You shouldnt take her help for granted.You mustnt do that.表示发出指示或提出请求Will you please take her to the library?Could you offer me work here?Can I as
6、k a question?May we ask what youre doing in this country？表示提出帮助或发出邀请Will you stay for lunch?Wouldnt you like to come with me?May I help you?Shall I put it in a box？表示提出建议You could ask the teacher for help.You should write him a letter.The cookies Susan made are delicious，you ought to try some.表示愿望Wo
7、uld you recommend the play to other people?I would like to know the date.Id love to go to your birthday party.Id rather not pay you now.表示义务和需要You must come at once.We have to wear uniforms at school.I ought to be on my way.4.情态动词难点透视英语中的情态动词虽然为数不多，但是要掌握好它们的用法并不容易。下面结合同学们在使用情态动词时不易掌握的难点谈几点看法。(1)can/
8、could/be able tocan表示可能性时，指的是理论上的可能，它通常不用来表示某事实际发生的可能性或真实性。如：Accidents can happen；anybody can make mistakes.如果我们要表达某事发生的实际可能性，要用may，could或might等。We may spend our summer holidays in Hangzhou this year.Will you answer the telephone？It could/may/might be your mother.could用来征求意见时，语气要比can委婉，但在回答问题时我们不能用c
9、ould，因为语气委婉，可能性就变小了。如：Could I use your telephone?Yes，please go ahead.在过去时态的肯定句中需要某种条件或努力做成某事，我们要用was/were able to而不能用could。如：It was a holiday and the children were able to go to the seaside.The girl worked hard so she was able to pass the final test.即学即练1选词填空can，could，be able toMy grandma is well ov
10、er eighty，but she can read without glasses.Being a wise person，he finally was able to find the place.The cheater said that he could turn the stone into gold.(2)must/have tomust与have to都可以表示“必须”的意思，但要注意以下两点区别：must只有现在时，而have to有现在时、过去时和将来时。如：We must work hard，or well fail in the examination.Years ago
11、，the poor girl had to leave school for lack of money.must表示主观看法，have to则侧重于客观需要。如：We must be strict with ourselves in everything.In cities with many cars，some people have to wear masks.“must动词原形”对目前的情况进行推测时以及用mustbev.ing形式对目前正在发生的情况进行推测时，疑问短语部分要与must之后的动词相一致。如：The mathematics teacher must be in the
12、office now，isnt he?“musthave过去分词”用来表示对已经发生的事情进行推论。如果句子中有过去的时间状语，疑问部分用助动词didnt；否则，疑问部分用havent或hasnt。如：The children must have watered the tomatoes yesterday，didnt they?The minister must have arrived in Shanghai，hasnt he?名师点津回答must引出的疑问句时，如果是否定的回答，不能用mustnt，而要用neednt或dont have to。Must we hand in our ex
13、ercise books now?Yes，you must.(No，you neednt./No，you dont have to.)我们现在就必须要交练习本吗？是的，必须。(不，不必。)即学即练2用适当的情态动词填空My sister is ill；my mother has to look after her.Theres a lot of noise from next door. They must be having a party.Must I return all the books in three days?Yes, you must(No, you neednt/dont
14、have to)If you must go, at least wait until the storm is over.(3)shall/willshall可以用来征求对方意见，用于第一、三人称。此外它也可以用来表示说话人的命令、警告、允诺、威胁或决心等，这时它用于第二、三人称。如：Shall she go to the concert with us this evening？(征求意见)You shall go to the front at once.(命令)Dont worry.You shall get the answer this very afternoon.(允诺)He
15、shall be sorry one day.I tell you.(警告)Nothing shall stop us from fighting against pollution.(决心)在表示将来的时间、条件状语从句中，不能用will。如：If it will rain tomorrow，we shall not go to the mountain village.(误)If it rains tomorrow，we shall not go to the mountain village.(正)当情态动词will表示意愿或决心时，是可以用于条件状语从句中。如：If you will
16、listen to me，Ill give you some advice on how to learn English.If you will come this way，the manager will meet you.即学即练3写出下列句子中shall表示的含义You shall fail if you dont work harder.警告You shall get an answer from me tomorrow.允诺You shall be punished for what youve done.威胁Shall I watch TV for a while？征求意见(4)
17、should/ought toshould除表示必要或义务外，还可表示推测。如：The American friends should be here now.“should/ought tohave过去分词”既可表示本该做而事实上没有做的事，也可以表示惊讶、责备、赞叹等情绪。如：You should have told her about it the day before yesterday.Its wonderful that you should have achieved so much in these years.ought to与should意思接近，大多数情况下二者可以互换，
18、但是should谈的是自己的主观看法，ought to则更多反映客观情况，在谈到法律、义务和规定时使用。如：We should/ought to help each other and learn from each other in our work.She is your mother，so you ought to support her.We ought to go and see Mary tomorrow，but I dont think we will.即学即练4用适当的情态动词填空Such a clever boy should fail the exam.We should
19、obey the school rules and work hard.Its already 10.She promised to come by 10. She should be here at any moment.(5)dare/needdare作为情态动词，主要用于疑问句、否定句和条件句中，一般不用于肯定句。aHow dare you say Im unfair?bHe darent speak English before such a crowd，dare he?cIf he dare break the rule，he will be punished.need表示“需要”或
20、“必须”，作情态动词用时，仅用于否定句、疑问句或条件句中，意为“有必要”。在肯定句中一般用must，have to，ought to或should代替。aYou neednt come so early.bNeed I finish the work today?Yes，you must./No，you neednt.cIf you need go there，please let me know.dare和need常用作实义动词，有时态、人称和数的变化。所不同的是，在肯定句中，dare后面通常接带to的不定式；在否定和疑问句中，dare后可接带to或不带to的不定式。aI dare to s
21、wim across the river.bHe doesnt dare(to)answer.cWe need time and money.dThe dining room needs/wants/requires cleaning every day.The dining room needs/wants/requires to be cleaned every day.eDoes he need to take the medicine three times a day?即学即练5用dare/need填空How dare you fight against him?No one dar
22、e say he had nothing on.Must I stay here?No, you needntYou need not be told twice about one single thing.(6)需要注意的几点：表示猜测，can一般不用于肯定句中，除非是“经验之谈”。这时can可以表示客观的可能性，并不牵涉具体的事情是否会发生；要表示某事发生的可能性时需要用could，may，might。Children can often get ill suddenly.Certain things in the home can be dangerous，especially if
23、you have young children.上面两句可以看作医务工作者或抚养过孩子的人说的话，属“经验之谈”。may和might表可能性的推测时都不用于疑问句中。如：Can/Could it be cloudy tomorrow？(正)May/Might it be cloudy tomorrow？(误)must表肯定推测时的否定式是cant/couldnt，不是neednt或mustnt。should/ought to动词原形：想必现在/将来会The dinner should/ought to be ready now.He should/ought to ring up this a
24、fternoon.will动词原形：将来一定/准会Try your best，and your wish will come true.二、过去将来时过去将来时表示在过去某一时间将要发生的动作或存在的状态。过去将来时常用在主句谓语动词为过去时态的宾语从句中。过去将来时句子中有时包含时间状语the next day，soon等。观察例句1I was about to get the letter.2They said the letter inside would explain what it was all about.3The director said he would meet the
25、 famous actor the next day.4They were going to find someone to take part in their bet when they saw Henry walking on the street outside.归纳用法1过去将来时的基本构成和用法过去将来时由“would动词原形”构成，主要表示从过去某一时间来看将要发生的动作(尤其用于宾语从句中)，还可以表示过去的动作习惯或倾向。Jeff knew he would be tired the next day.He promised that he would not open th
26、e letter until 2 oclock.She said that she wouldnt do that again.2表示过去将来时的其他表达法(1)was/were going to动词原形：该结构有两个主要用法，一是表示过去的打算，二是表示在过去看来有迹象表明将要发生某事。I thought it was going to rain.(2)was/were to动词原形：主要表示过去按计划或安排要做的事情。She said she was to get married next month.(3)was/were about to动词原形：表示在过去看来即将要发生的动作，由于本
27、身已含有“即将”的意味，所以不再与表示具体的将来时间状语连用。I was about to go to bed when the phone rang.(4)was/were现在分词：表示在过去看来即将发生的动作，通常可用于该结构中的动词有come，go，leave，arrive，begin，start，stop，close，open，die，join，borrow，buy等瞬间动词。Jack said he was leaving tomorrow.即学即练6完成句子1莉莉说晚上将有一场音乐会。Lily said there would be a concert that evening.2
28、她确信她会成功。She was sure she would succeed3我想知道我们什么时候出发。I wanted to know when we were going to set off4他说运动会就要开始了。He said the sport meet was about to begin5他说他今晚要走。He said he was leaving tonight.用适当的情态动词填空1Cant you stay a little longer?Its getting late.I really must go now.My daughter is at home alone.2
29、He couldnt sleep，when he got on such a hunt for an idea until he had caught it.3You mustnt park here！Its an emergency exit.4You neednt give me a lift.I want to walk home for exercise.5Will she be ten years old next month?6The police still havent found the lost child，but theyre doing all they can7Why
30、 are your eyes so red？You cant have slept well last night.Yeah，I stayed up late writing a report.8According to the newlymade traffic regulation，whoever drives through red lights shall be fined at least 200 dollars.9George cant have gone too far.His coffee is still warm.10Afraid of water，I wonder if
31、I dare jump into the pool and swim.短文语法填空Im sorry to learn that youve failed in the examination.You said you could 1.have passed(pass) it but you were too nervous.But things 2.may not be like that.If you had made enough 3.preparations(preparation)，you wouldnt 4.have been too nervous.I think the real
32、 reason for your failure 5.must be that you didnt do your best.When an opportunity comes，we 6.should/ought to grasp it 7.tightly(tight)But if we only wait for the good opportunity 8.to come(come)，it will never come.As a saying 9.goes(go)，practice makes perfect.If you 10.will take more efforts on your study，you are sure to make it next time.