
吼吼、我知道。英文中的情态动词主要有:can,could;may,might;must;ought;need;dare,dared,另外,shall,will,should,would在一定的场合也可用作情态动词。
情态动词英语叫Modal verb,它就是mood表示语气对应的形容词词形式,一般这个词是没有缩写的,但是情态动词它属于助动词,助动词叫auxiliary verb,它的缩写是aux。
四大分类:
①只做情态动词:may, might, must…
②可做情态动词又可做实义动词:如:need, dare.can...
③具有情态动词特征:have(had,has) to,used to, ought to。
④可做情态动词又可作助动词:如:shall(should),will(would)。
注意:
①mustn't代表强烈禁止, must表示主观,是自发的,have to表示客观,意为不得不去做某事。
②美式英语中常用must not ,mustn't是must not的缩写. mayn't,mightn't和shan't也很少用。
情态动词有:can, could, may, might, ought to, have to, need, shall, should, will, would, dare
情态动词(Modal verb)本身有一定的词义,表示语气的单词。但是不能独立作谓语,只能和动词原形一起构成谓语。情态动词用在行为动词前,表示说话人对这一动作或状态的看法或主观设想。 情态动词虽然数量不多,但用途广泛。
用法:
首先它是动词,而且不同于行为动词,行为动词表示的是可以通过行为来表达的动作(如写,读,跑),而情态动词只是表达的一种想法(如能,也许,敢)。
用法是:情态动词+行为动词原形
例句:I can read this sentence in English.
我能用英语读这句话。
情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语,只能和其他动词原形构成谓语。
We can be there on time tomorrow.
我们明天能按时去那儿。
情态动词+havedone是一种虚拟语气,和情态动词+动词原形的区别是:用原型表示事情发生在现在或将来,而用havedone,表示事情发生在过去。例如,Youmustbetirednow。(你现在一定很累)Youmusthaveseenthefilm。(你一定看过这部电影)指的是你过去一定看过。考试常考这么几种:musthavedone(过去)一定做过某事Itmusthaverainedlastnight。(昨晚一定下雨了)cann'thavedone(过去)一定没有做过某事Hecann'thaveseenthefilm,becausehedoesn'sknowanyingaboutit。(他一定没看过那部电影,因为他对它一无所知)注意:千万不能用mustn't,因为它是“禁止,绝不可以”的意思couldhavedone(过去)本来可以做成某事实际上却没有IcouldhavesucceededinthegameifIhadn'thaveacold。(如果我没感冒的话,我可能已经在比赛中成功了)shouldhavedone(过去)应该做某事而没有做Youshouldhavecleanedyourroomyesterday。(你昨天就应该把屋子打扫了)而实际上却没有
1 情态动词的语法特征 1) 情态动词不能表示正在发生或已经发生的事情,只表示期待或估计某事的发生。 2) 情态动词 除ought 和have 外,后面只能接不带to 的不定式。 3) 情态动词没有人称,数的变化,即情态动词第三人称单数不加-s。 4) 情态动词没有非谓语形式,即没有不定式,分词,等形式。 2 比较can 和be able to 1)can could 表示能力;可能 (过去时用could), 只用于现在式和过去式(could)。be able to可以用于各种时态。 They will be able to tell you the news soon. 他很快就能告诉你消息了。 2)只用be able to a. 位于助动词后。 b. 情态动词后。 c. 表示过去某时刻动作时。 d. 用于句首表示条件。 e. 表示成功地做了某事时,只能用was/were able to, 不能用could。 He was able to flee Europe before the war broke out. = He managed to flee Europe before the war broke out. 注意:could不表示时态 1)提出委婉的请求,(注意在回答中不可用could)。 --- Could I have the television on? --- Yes, you can. / No, you can't. 2)在否定,疑问句中表示推测或怀疑。 He couldn't be a bad man. 他不大可能是坏人。 3 比较may和might 1) 表示允许或请求;表示没有把握的推测;may 放在句首,表示祝愿。 May God bless you! He might be at home. 注意: might 表示推测时,不表示时态。只是可能性比may 小。 2) 成语: may/might as well,后面接不带to 的不定式,意为"不妨"。 If that is the case, we may as well try. 典型例题 Peter ___come with us tonight, but he isn't very sure yet. A. must B. may C. can D. will 答案B. 表可能性只能用may. 此句意可从后半句推出。 4 比较have to和must 1) 两词都是'必须'的意思,have to 表示客观的需要, must 表示说话人主观上的看法,既主观上的必要。 My brother was very ill, so I had to call the doctor in the middle of the night. 我弟弟病得很厉害,我只得半夜里把医生请来。(客观上需要做这件事) He said that they must work hard. 他说他们必须努力工作。(主观上要做这件事) 2) have to有人称、数、时态的变化,而must只有一种形式。但must 可用于间接引语中表示过去的必要或义务。 He had to look after his sister yesterday. 3) 在否定结构中: don't have to 表示"不必" mustn't 表示"禁止", You don't have to tell him about it. 你不一定要把此事告诉他。 You mustn't tell him about it. 你一定不要把这件事告诉他。 5 must表示推测 1) must用在肯定句中表示较有把握的推测,意为"一定"。 2) must表对现在的状态或现在正发生的事情的推测时, must 后面通常接系动词be 的原形或行为动词的进行式。 You have worked hard all day.You must be tired. 你辛苦干一整天,一定累了。(对现在情况的推测判断) He must be working in his office. 他一定在办公室工作呢。 比较: He must be staying there. 他现在肯定呆在那里。 He must stay there. 他必须呆在那。 3) must 表示对已发生的事情的推测时,must 要接完成式。 I didn't hear the phone. I must have been asleep. 我刚才没有听到电话,我想必是睡着了。 4) must表示对过去某时正发生的事情的推测,must 后面要接不定式的完成进行式。 ---Why didn't you answer my phone call? ---Well, I must have been sleeping, so I didn't hear it. 5) 否定推测用can't。 If Tom didn't leave here until five o'clock, he can't be home yet. 如果汤姆五点才离开这儿,他此时一定还未到家。 6 表示推测的用法 can, could, may, might, must 皆可表示推测,其用法如下: 1)情态动词+动词原形。 表示对现在或将来的情况的推测,此时动词通常为系动词。 I don't know where she is, she may be in Wuhan. 2)情态动词+动词现在进行时。 表示对现在或将来正在进行的情况进行推测。 At this moment, our teacher must be correcting our exam papers. 这时,我们老师想必在批改试卷。 3)情态动词+动词完成时。 表示对过去情况的推测。 We would have finished this work by the end of next December. 明年十二月底前我们很可能已完成这项工作了。 The road is wet. It must have rained last night. 地是湿的,昨天晚上一定下雨了。 4)情态动词+动词的现在完成进行时。 表示对过去正在发生事情的推测。 Your mother must have been looking for you. 你妈妈一定一直在找你。 5)推测的否定形式,疑问形式用can't, couldn't表示。 Mike can't have found his car, for he came to work by bus this morning. 迈克一定还没有找回他的车,因为早上他是坐公共汽车来上班的。 注意:could, might表示推测时不表示时态,其推测的程度不如can, may。 7 情态动词+ have +过去分词 1) may(might) have + done sth, can (could) have + done sth 表示过去,推测过去时间里可能发生的事情。 Philip may (might) have been hurt seriously in the car accident. Philip can (could) have been hurt seriously in the car accident. 2) must have +done sth,对过去时间里可能发生的事情的推测,语气较强,具有"肯定","谅必"的意思。 ---Linda has gone to work, but her bicycle is still here. ---She must have gone by bus. 3) ought to have done sth, should have done sth 本应该做某事,而事实上并没有做。否定句表示"不该做某事而做了"。 You ought to (should) have been more careful in this experiment. He ought not to have thrown the old clothes away.(事实上已扔了。) ought to 在语气上比should 要强。 4) needn't have done sth 本没必要做某事 I dressed very warmly for the trip, but I needn't have done so. The weather was hot. 5) would like to have done sth 本打算做某事 I would like to have read the article, but I was very busy then. 8 should 和ought to should 和ought to 都为"应该"的意思,可用于各种人称。 ---Ought he to go? ---Yes. I think he ought to. 表示要求,命令时,语气由 should(应该)、had better最好)、must(必须)渐强。 9 had better表示"最好" had better 相当于一个助动词,它只有一种形式,它后面要跟动词原形。 had better do sth had better not do sth It is pretty cold. You'd better put on my coat. She'd better not play with the dog. had better have done sth表示与事实相反的结果,意为"本来最好"。 You had better have come earlier. 10 would rather表示"宁愿" would rather do would rather not do would rather… than… 宁愿……而不愿。 还有would sooner, had rather, had sooner都表示"宁愿"、"宁可"的意思。 If I have a choice, I had sooner not continue my studies at this school. I would rather stay here than go home. = I would stay here rather than go home. 典型例题 ----Shall we go skating or stay at home? ----Which ___ do? A. do you rather B. would you rather C. will you rather D. should you rather 答案B。本题考查情态动词rather的用法,would rather +do sth 意为"宁愿",本题为疑问句,would 提前,所以选B。 11 will和would 注意: 1)would like; Would like to do = want to 想要,为固定搭配。 Would you like to go with me? 2)Will you…? Would you like…? 表示肯定含义的请求劝说时,疑问句中一般用some, 而不是any。 Would you like some cake? 3)否定结构中用will,一般不用would, won't you是一种委婉语气。 Won't you sit down? 12 情态动词的回答方式 问句 肯定回答 否定回答 Need you…? Yes, I must. No,I needn't Must you…? /don't have to. 典型例题 1)---Could I borrow your dictionary? ---Yes, of course, you____. A. might B. will C. can D. should 答案C.could表示委婉的语气,并不为时态。答语中of course,表示肯定的语气,允许某人做某事时,用can和 may来表达,不能用could或might。复习: will 与you连用,用来提出要求或下命令。should与you 连用,用来提出劝告。 2)---Shall I tell John about it? ---No, you ___. I've told him already. A. needn't B. wouldn't C. mustn't D. shouldn't 答案A。needn't 不必,不用。 wouldn't 将不, 不会的。 mustn't 禁止、不能。 shouldn't 不应该。本题为不需要,不必的意思,应用needn't。 3)---Don't forget to come to my birthday party tomorrow. ---______. A. I don't B. I won't C. I can't D. I haven't 答案B. will既可当作情态动词,表请求、建议、也可作为实义动词表"意愿、意志、决心",本题表示决心,选B。 13 带to 的情态动词 带to 的情态动词有四个:ought to, have to, used to, be to, 如加上have got to ,(=must), be able to,为六个。它们的疑问,否定形式应予以注意: Do they have to pay their bill before the end of the month? She didn't use to play tennis before she was fourteen. You ought not to have told her all about it. Ought he to see a heart specialist at once.? ought to 本身作为情态动词使用。其他的词作为实义动词使用,变疑问,否定时,须有do 等助动词协助。 典型例题 Tom ought not to ___ me your secret, but he meant no harm. A.have told B.tell C.be telling D. having told 答案A。由于后句为过去时,告诉秘密的动作又发生在其前因,此地应用过去完成时,但它在情态动词 ought to 后,所以用have。 14 比较need和dare 这两词既可做实义动词用,又可做情态动词用。作为情态动词,两者都只能用于疑问句,否定句和条件句。 need 作实义动词时后面的不定式必须带to,而dare作实义动词用时, 后面的to 时常可以被省略。 1) 实义动词: need (需要, 要求) need + n. / to do sth 2) 情态动词: need,只用原形need后加do,否定形式为need not。 Need you go yet? Yes, I must. / No, I needn't. 3) need 的被动含义:need, want, require, worth(形容词)后面接doing也可以表示被动: need doing = need to be done
情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语, 只能和其他动词原形构成谓语。编辑本段分类: 情态动词有四类: ①只做情态动词:must,can(could),may(might),ought to ②可做情态动词又可做实义动词:need,dare ③可做情态动词又可做助动词:shall(should),will(would) ④具有情态动词特征:have(had) to,used to编辑本段位置: 情态动词在句中放在谓语动词之前, 谓语动词前若有助动词,则在助动词之前,疑问句中, 情态动词则在主语之前。 I can see you. Come here. 我能看见你,过来吧。 He must have been away. 他一定走了。 What can I do for you? 你要什么? How dare you treat us like that! 你怎能那样对待我们!编辑本段特点: 情态动词无人称和数的变化, 情态动词后面跟的动词需用原形,否定式构成是在情态动词后面加 "not"。 个别情态动词有现在式和过去式两种形式, 过去式用来表达更加客气, 委婉的语气, 时态性不强, 可用于过去,现在或将来。情态动词属非及物动词,故没有被动语态。 He could be here soon. 他很快就来。 We can't carry the heavy box. 我们搬不动那箱子。 I'm sorry I can't help you. 对不起,我帮不上你。 基本助动词与情态助动词最主要的区别之一是,基本助动词本身没有词义,而情态助动词则有自己的词义,能表示说话人对有关动作或状态的看法,或表示主观设想: What have you been doing since? (构成完成进行体,本身无词义) I am afraid I must be going. (一定要) You may have read some account of the matter. (或许已经) 除此之外,情态助动词还有如下词法和句法特征: 1) 除ought和used以外,其他情态动词后面只能接不带to的不定式。如果我们把ought to和used to看做是固定词组的话,那么,所有情态动词无一例外地只能接不带to的不定式: We used to grow beautiful roses. I asked if he would come and repair my television set. 2) 情态助动词在限定动词词组总是位居第一: They need not have been punished so severely. 3) 情态助动词用于第三人称单数现在时的时候,没有词形变化,即其词尾无-s形式: She dare not say what she thinks. 4) 情态动词没有非限定形式,即没有不定式和分词形式,也没有相应的动名词: Still, she needn't have run away. 5) 情态助动词的“时”的形式并不是时间区别的主要标志。在不少场合,情态助动词的现在时和过去时形式都可以表示现在、过去或将来时间: Would you mind very much if I ask you to do something? She told him he ought not to have done it. 6) 情态助动词之间是相互排斥的,即在一个限定动词词组中只能出现一个情态助动词,但有时却可以与have和be基本助动词连用: You should have washed the wound. Well, you shouldn't be reading a novel.编辑本段用法 首先它是动词,而且不同于行为动词,行为动词表示的是可以通过行为来表达的动作(如写,读,跑),而情态动词只是表达的一种想法(如能,也许,敢)。 用法是:情态动词+行为动词原形 例句:I can read this sentence in English. 我能用英语读这句话。 情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语, 只能和其他动词原形构成谓语。 We can be there on time tomorrow.我们明天能按时去那儿。 May I have your name? 我能知道你的名字吗? Shall we begin now?我们现在就开始吗? You must obey the school rules.你必须遵守校规。 情态动词数量不多,但用途广泛,主要有下列: can (could), may (might), must, need, ought to, dare (dared), shall (should), will (would),have (to) ,had better.编辑本段功能 助动词(auxiliary)主要有两类:基本助动词(primary auxiliary)和情态助动词(modal auxiliary)。基本助动词有三个:do, have和be;情态助动词有十三个:may, might; can, could; will, would; shall, should; must, need, dare, used to, ought to. 上述两类助动词的共同特征是,在协助主动词构成限定动词词组时,具有作用词的功能: 1) 构成否定式: He didn't go and neither did she. The meeting might not start until 5 o'clock. 2) 构成疑问式或附加疑问式: Must you leave right now? You have been learning French for 5 years, haven't you? 3) 构成修辞倒装: Nowhere can he obtain any information about his sister. Hardly had he arrived when she started complaining. 4) 代替限定动词词组: A: Who can solve this crossword puzzle? B: Tom can. A: Shall I write to him? B: Yes, do.