Mba,mpa,mpacc联考英语词汇助动词

1、Mba,mpa,mpacc联考英语词汇助动词【mba加油站】一、助动词助动词不能独立使用，但可以帮助实义动词构成不同的时态和语态，表达不同的意义。常见的助动词有:be， do, have, shall, will等。1. be 的用法(1)与动词的现在分词构成各种进行时态。I am playing computer games.What were you doing at 8 oclock this moming?The children have been watching TV all moming.(2) 与动词的过去分词构成被动语态。The book was written in En

2、glish.English is spoken all over the world.The bridge is being built.The book has been translated into many languages.2. do 的用法(1)在一般现在或一般过去时态中，构成否定或疑问结构。She doesnt speak English.Did you see him in the party?I dont think you are right.(2) 构成否定的祈使句。Dont be so careless！Dont speak so fast！(3) 在一般现在或一般过

3、去时态中的肯定句中，强调动词，意为一定，务必，的确。Do be careful！I did go, but she wasnt in.3. have 的用法(1)与动词的过去分词构成完成时态。He has just left.Have you ever been to the Great Wall?They had got everything ready before I came.(2) 用于虚拟语气。If you had posted the letter, Mother would have received it last Monday.Had I left earlier， I w

4、ouldn t have missed the train.4. shall 和will的用法助动词shall 和will和动词原形构成将来时。shall/should 仅限于第一人称， will/would可用于所有人称。Will you stay here a little longer?I shall go to Hong Kong next week.He told me that he would see me off at the station.【注意 shall/should 和will/would 也可用作情态动词。 二、情态动词情态动词本身有词义，但不能独立使用，要和另一动

5、词一起构成谓语，表示说话人的某种情绪，没有人称和数的变化。英语中的情态动词主要有can， cou1d, may, might, must,will, would, shall, should, ought to, dare, need 等。大多数情态动词都可以表示推测，其肯定程度由低到高为mightmaycouldcanshouldought towouldwillmust。1. can/could 和may/mightcould 是can 的过去式形式， might 是may 的过去式形式。(1)表示能力，意为能够。can表示天生的或学到的能力， could 表示过去天生的或学到的能力may

6、 和might不能用来表示能力。Bill is only nine months old and he can already stand up.He can speak several foreign languages.As a child, he could play the piano.【注意】can 与is/am/are able to 的区别 can 可与is/am/are able to互换使用，但在将来时和完成时中必须用will be able to和have/has been able to 。Can you type? (=Are you able to type?)I w

7、ont be able to come, I am afraid.We havent been able to reach an agreement.表示经过努力成功地完成某一具体动作时，只能用was/were able to, succeed in或manage to ，不能用could; 但如果表示某一动作没有成功，则可以使用couldnt。After years of hard work he was able to win the prize.I was able to get the ticket I wanted.I couldn t/wasnt able to find the

8、person I was looking for.(2) 表示允许，意为可以。can/could 和may/might 都可以表示请求别人允许，但may/might can/could 更为正式，语气也比can/could 更加委婉客气。1 )can 和may 可用于肯定句、否定句和疑问句中， might 和could 仅用于疑问句中。You can/may take the book home.You cant/may not smoke here.Can /Could /May/Might I borrow your bike?-Of course, you can/may.一No， yo

9、u cant/may not/mustnt.2)在请求帮助时不可用May，Might you ?提问，要用can 或could。Can/Could you tell me the way to the post office?- Yes, of course.-No, Im afraid I can t.3) 在明确表示过去的许可时，要用could 或might，不用can 或may。She asked me if she could/might get another drink.He told me that I could/might smoke in the room.(3) 表示推测

10、，意为可能。can/could 和may/might 都表示可能发生的事。1 )may 不能用于疑问句中， can 不能用于肯定句中。否定句中may/might not 表示可能不而can/could not 表示不可能并往往含有不相信之意。Might/Could/Can this be true?Mary may/might/could be at home.Mary may/might/could/can not be at home.2) can/could 可以用于肯定句，表示某人或某物一时的特点，意为有时，往往。It can/could be very cold in this ar

11、ea in January.Such an accident can/could happen.A woman can/could do anything when jealousHe could be very naughty when he was a little boy.3 )表示过去的可能时，要用could 和might，不用can 和may。Mary wondered what he could/might mean.He said she could/might be working late that night.4) can/could/may/might+have+过去分词

12、所表达的意义 can/could/may/might+have+过去分词表示对过去的推测。The little boy can/could/may/might not have read the story.Where can/could/might he have gone?He could/may/might have lost the key. could/might +have+过去分词表示过去能够做而没有做某事，意为本能够。You could/might have told me earlier.You could/might have told me you were going

13、to be late!(4)may/might 表示祝愿或建议。May our friendshlp live long!May you live to be a hundred! 2. must(1)表示义务，意为必须。We must be there on time.He must do as he is told.I must go to the bank to get some money.【注意】 must 否定形式的特殊意义 mustnt 不是must 否定形式， mustnt 意为不许，禁止。You mustn t smoke in the room.You must not t

14、ell others.用must 提问的句子，肯定回答用must ，否定回答用neednt 或dont have to 。Must I go so soon?-Yes, you must.-No, you needn t/don t have to. must 和have to 的区别must 强调主观看法，表示说话人主观上认为有必要做某事；have to 强调客观需要，表示因客观条件要求不得不做某事。She must do it herself. I shant help her.She has to do it herself. She has got no one to help her

15、.must 和have to 有时可以互换使用，但have to 可以用于不同的时态， must 只用于现在时，有时也用来表示将来和过去。I must/have to leave now.Well have to buy another TV set.He had to do it again.My mother said that I must be home early.(2)表示推测，意为“一定”。 must+动词原形表示对现在肯定的推测，其否定形式为cant +动词原形。You must be joking.You mustbe tired after the long walk. m

16、ust+have+过去分词表示对过去肯定的推测，其否定形式为cant/couldnt+have+过去分词。He hasnt arrived yet. He must have lost his way.You are very happy. You must have heard the news.Jones couldnt have caught 9 oclock train for he left his house at 9:15.3. shall( 1 )表示允许，用于第一人称疑问句中，表示愿意按对方的指示去做。Shall we meet in the evening? (建议)-Ye

17、s, lets, (shall we)?-No, Id rather not.Shall I go there tomorrow? (提议为他人做事)-Yes， please.-No， thank you.(2) 表示意愿或决心，用于第二、三人称陈述句中，不可缩写。shall 表示的意志是说话人的意志，不是句中主语的意志。You shall have a lot of money.She shall get this paper in the evening.He shall get what he deserves.(3) 表示义务、规定，用于法律、条约、协定等文件中，仅用于第三人称。The

18、 new regulation shall take effct on Jan. 1.The interest shall be divided into five parts.4. Will和would( 1 )表示请求， will和would 可以互换使用， would 的语气更委婉，也可以用wont。Will/Would/Wont you have a walk with me? (邀请)-(Yes，) Id like/love to.-No， I d prefer not to，thank you.Will/Would you (please) open the door? (请求)-

19、Yes, of course.-No, Im afraid I cant.(2) 表示意图，意愿。Ill trouble you for the pencil.He wont lend me the money.She wouldnt come to the zoo-he was afraid of animals.【注意】表示意愿时， wil1也可以用在if 引导的条件句中，表示各种愿望。If you will try again, you will succeed.If he wont go with you, I shall ask somebody else.人作主语， will/wo

20、uld 表示固执己见或拒不听从劝告，意为非得，偏偏。If you will go to bed so late, no wonder youre tired.He would keep telling those dreadful stories.物作主语， will/would 表示固有的性质、倾向，用于否定句，意为就是不。The door wont shut.My pen wouldnt write.(3)表示习惯或自然的倾向。1) will代替一般现在时， would 代替一般过去时，表示某人特有的习惯和行为。In fine weather, he will often sit in t

21、he sun for hours.She would spend hours in the bathroom or on the phone.2) will可以用于下列习惯用语中，意为难免。Accidents will happen.Boys will be boys.3) 当主语为第三人称时， will 同一般现在时一样，表示真理或事物的品质。Oil will float on water.Fish will die out of water.Water will boil at 100C.(4) 表示对现在的推测，意为可能，该接近肯定。They will/would be home by

22、this time.They will/would be watching TV now.It would be about ten oclock when they left home.Mary will/would have arrived by now.(5) would 和used to 的区别1) used to 强调如今已不存在的过去习惯性动作或状态，与现在的情况形成对比。He used to smoke a lot (,but he doesnt any longer) .There used to be a church.People used to think that th

23、e earth was flat (,but they dont think so now).2) would 强调过去某种特定情况下的动作，是完全过去的事情，与现在没有关系。would 只表示动作，不表示状态。Sometimes she would take a walk in the park.Whenever I had difficulties， I would ask him for help.3) used to 表示习惯性动作时，往往可以和would 互换使用。When we were children, we used to/would go skating every win

24、ter.She used to/would spend every penny she eamed on clothes.When he was young, he always used to(=would always) get up at 5.5. should 和ought to( 1 ) should 和ought to 表示义务，意为应该，用法完全相同，只不过ought to 的语气稍重。should/ ought to have+过去分词表示过去应该做某事而却没做。You should/ought to do as he says.You really should/ought

25、not to tell such a lie.You should/ought to have told me that earlier.I should/ought not to have hurt her feeling.(2) should 和ought to 表示推测，意为估计，可能不如may， might, could 表示可能常用。He should/ought to arrive at noon.She should/ought to be working in the lab.I should have finished reading it by Friday.(3) sho

26、uld 表示客气的请求或表达不成熟的意见。I should like to make a phone, if possible.I should imagine it will take about three hours.I should say shes over forty.(4) should 用于疑问句或感叹句中，表示意外、惊异等，与how， why, who 连用。How should I know?Why should you be worrying?Who should come to meet us but the manager！(5) should 用于从句中，表示虚拟的

27、语气。I suggest that we should discuss it at once.It is a pity that she should fail in the exam.If it should rain tomorrow, what should we do?Take an umbrella with you in case it should rain.6. needneed 既可以用作情态动词，也可以用作实义动词，表示必要。( 1) need 用作情态动词时，没有人称和数的变化，后接动词原形，否定形式为need not 或need的，仅用于疑问句和否定句中。You nee

28、dnt talk so loud.Need he fmish the work today?-Yes, he must.-No, he neednt.【注意】 need 用作情态动词时，可以和带有否定意义的词hardly， never, seldom, rarely,scarcely, nobody 等连用，表示否定的意义。He need never know.I need hardly tell you that the work is dangerous.There need be no hurry, need there?Nobody need be afraid of catching the disease.( neednt +have+过去分词表示过去没有必要做某事而却做了。You neednt have told her the news.Need you have sold the house?-Yes， I had to.-No, I neednt have.(2) need 用作实义动词时，有人称和数的变化