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初中英语情态动词知识点讲解

线话英语|2015-05-11 16:40:14

21. 初中英语情态动词知识点讲解

  21.1 初中英语情态动词的语法特色 CopyRight .com

   1)初中英语 情态动词不能表示正在发生或已经发生的事情,只表示等候或估计某事的发生。

   2) 情态动词 除ought 和have 外,后面只能接不带to 的不定式。 CopyRight .com

   3) 情态动词没有人称,数的变更,即情态动词第三人称单数不加-s。 内容来自

   4) 情态动词没有非谓语形式,即没有不定式,分词,等形式。 CopyRight .com

  21.2 比较can 和be able to的初中英语情态动词

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  1)can could 表示才干;可能 (过去时用could),

 

 

  只用于现在式和从前式(could)。be able to能够用于各种时态。

   They will be able to tell you the news soon. 他很快就能告诉你消息了。

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  2)只用be able to 内容来自

    a. 位于助动词后。 CopyRight .com

    b. 情态动词后。

 

 

    c. 表示从前某时刻动作时。 内容来自

    d. 用于句首表示前提。

    e. 表示成功地做了某事时,只能用was/were able to, 不能用could。

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     He was able to flee Europe before the war broke out. CopyRight .com

    = He managed to flee Europe before the war broke out.

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  初中英语情态动词注意:could不表示时态 内容来自

  1)提出委婉的恳求,(留神在答复中不可用could)。

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     --- Could I have the television on?

     --- Yes, you can. / No, you can't. CopyRight .com

  2)在否定,疑问句中表示推测或猜疑。

       He couldn't be a bad man.  

 

 

       他不大可能是坏人。 内容来自

  21.3 比较may和might 内容来自

  1) 表示允许或要求;表示不控制的推测;may 放在句首,表示庆祝。 内容来自

      May God bless you!

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      He might be at home.

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  初中英语情态动词注意: might 表示推测时,不表示时态。只是可能性比may 小。 CopyRight .com

  2) 成语: may/might as well,后面接不带to 的不定式,意为"不妨"。

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      If that is the case, we may as well try.

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  初中英语情态动词典型例题

   Peter ___come with us tonight, but he isn't very sure yet.

 

 

    A. must  B. may  C. can  D. will

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   答案B. 表可能性只能用may. 此句意可从后半句推出。 CopyRight .com

  21.4 比较have to和must

 

 

  1) 两词都是'必须'的意思,have to 表示客观的须要, must 表示谈话人主观上的看法,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,我只得深夜里把医生请来。(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)

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  2) have to有人称、数、时态的变革,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。

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  He had to look after his sister yesterday.

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  3) 在否定构造中: don't have to  表示"不必" CopyRight .com

            mustn't    表示"禁止",

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     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知他。

  21.5 must表示推测

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   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产生的事件的推测时, must 后面通常接系动词be 的本相或举动动词的进行式。 CopyRight .com

     You have worked hard all day.You must be tired.  你辛苦干一终日,必定累了。(对现在情形的揣测判断) 内容来自

     He must be working in his office. 他一定在办公室工作呢。 CopyRight .com

   初中英语情态动词比较:

 

 

      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。

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     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。 内容来自

   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。

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    ---Why didn't you answer my phone call?

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    ---Well, I must have been sleeping, so I didn't hear it. 内容来自

   5) 否定推测用can't。

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     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。

  21.6 表示推测的用法

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   can, could, may, might, must 皆可表示推测,其用法如下: CopyRight .com

  1)初中英语情态动词+动词原形。 内容来自

    表示对当初或将来的情况的揣摩,此时动词通常为系动词。

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    I don't know where she is, she may be in Wuhan. CopyRight .com

  2)情态动词+动词现在进行时。

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    表示对现在或未来正在进行的情况进行推测。

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    At this moment, our teacher must be correcting our exam papers.

 

 

    这时,咱们老师想必在批改试卷。

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  3)初中英语情态动词+动词实现时。

 

 

    表示对过去情况的推测。

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    We would have finished this work by the end of next December.

    明年十二月底前咱们很可能已完成这项工作了。

 

 

    The road is wet. It must have rained last night. CopyRight .com

    地是湿的,昨天晚上一定下雨了。

 

 

  4)情态动词+动词的当初实现进行时。 内容来自

    表示对过去正在发生事件的推测。 CopyRight .com

    Your mother must have been looking for you.

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    你妈妈一定始终在找你。 CopyRight .com

  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.

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    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。

 

 

   初中英语情态动词注意:could, might表示推测时不表示时态,其推测的程度不如can, may。 CopyRight .com

  21.7 情态动词+ have +过去分词

 

 

  1) may(might) have + done sth, can (could) have + done sth 表示过去,推测过去时光里可能发生的事情。

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    Philip may (might) have been hurt seriously in the car accident.

 

 

    Philip can (could) have been hurt seriously in the car accident.

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  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,存在"肯定","谅必"的意思。 CopyRight .com

   ---Linda has gone to work, but her bicycle is still here.

   ---She must have gone by bus.

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  3) ought to have done sth, should have done sth

    本应该做某事,而事实上并不做。否定句表示"不该做某事而做了"。

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    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。 内容来自

  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. CopyRight .com

  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. CopyRight .com

  21.8 should 跟ought to

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    should 和ought to 都为"应当"的意思,可用于各种人称。

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    ---Ought he to go? CopyRight .com

    ---Yes. I think he ought to.

    表示请求,命令时,语气由 should(应该)、had better最好)、must(必须)渐强

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  21.9 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。 CopyRight .com

    had better do sth

 

 

    had better not do sth

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    It is pretty cold. You'd better put on my coat. 内容来自

    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"。 内容来自

    You had better have come earlier.

 

 

  21.10 would rather表示"甘心"

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   would rather do

   would rather not do

 

 

   would rather… than…  宁愿……而不愿。 CopyRight .com

   还有would sooner, had rather, had sooner都表示"宁愿"、"宁肯"的意思。 CopyRight .com

   If I have a choice, I had sooner not continue my studies at this school. CopyRight .com

   I would rather stay here than go home. = I would stay here rather than go home.

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  初中英语情态动词典型例题

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  ----Shall we go skating or stay at home?

  ----Which ___ do?     

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  A. do you rather  B. would you rather  C. will you rather  D. should you rather

  谜底B。本题考察情态动词rather的用法,would rather +do sth 意为"情愿",本题为疑问句,would 提前,所以选B。

 

 

  21.11 will和would

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   初中英语情态动词注意:

   1)would like; Would like to do = want to 想要,为固定搭配。

     Would you like to go with me?

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   2)Will you…? Would you like…? 表现断定含意的请求奉劝时,疑难句中个别用some, 而不是any。

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     Would you like some cake?

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   3)否定结构中用will,一般不用would, won't you是一种委婉语气。 CopyRight .com

     Won't you sit down? CopyRight .com

  21.12 情态动词的回答方式 CopyRight .com

     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.

 

 

  典范例题

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  1)---Could I borrow your dictionary?

 

 

    ---Yes, of course, you____. 

 

 

    A. might B. will  C. can  D. should

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    答案C.could表示委婉的语气,并不为时态。答语中of course,表示确定的语气,允许某人做某事时,用can和 may来表白,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? CopyRight .com

    ---No, you ___. I've told him already.   内容来自

    A. needn't  B. wouldn't  C. mustn't  D. shouldn't

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    答案A。needn't 不必,不用。 wouldn't 将不, 不会的。 mustn't 制止、不能。 shouldn't 不应该。本题为不需要,不必的意思,应用needn't。 内容来自

  3)---Don't forget to come to my birthday party tomorrow. 内容来自

    ---______.

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    A. I don't  B. I won't  C. I can't D. I haven't 内容来自

    答案B. will既可当作情态动词,表要求、倡导、也可作为实义动词表"意愿、意志、信心",本题表示信念,选B。

 

 

  21.13 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,否认情势应予以留心:

    Do they have to pay their bill before the end of the month?

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    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.?

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    ought to 本身作为情态动词应用。其余的词作为实义动词利用,变疑问,否定时,须有do 等助动词辅助。

  初中英语情态动词典型例题

 

 

   Tom ought not to ___ me your secret, but he meant no harm. 

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   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。 CopyRight .com

  21.14 比拟need和dare CopyRight .com

    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,两者都只能用于疑难句,否定句跟条件句。 need 作实义动词时后面的不定式必需带to,而dare作实义动词用时, 后面的to 时常可能被省略。

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  1) 实义动词: need (需要, 请求)

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          need + n. / to do sth

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  2)初中英语 情态动词: need,只用原形need后加do,否定形式为need not。

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    Need you go yet? 内容来自

    Yes, I must. / No, I needn't.

 

 

  3) need 的被动含意:need, want, require, worth(形容词)后面接doing也可以表示被动:  内容来自

    need doing = need to be done

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初中英语情态动词

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