整理-情态动词

1、情态动词情态动词一、特征一、特征 1) 情态动词本身有词义情态动词本身有词义,表示说话人的语气或情态表示说话人的语气或情态,但词义不完全但词义不完全,不能单独作谓语动不能单独作谓语动 词词,只能和不带只能和不带to的动词不定式的动词不定式(即动词原型即动词原型)(ought等除外等除外)一起构成谓语动词一起构成谓语动词. 2) 情态动词所表示的情态有情态动词所表示的情态有: 命令、允许、请求、拒绝、愿望、愿意、义务、必要、命令、允许、请求、拒绝、愿望、愿意、义务、必要、可能、敢于、需要等可能、敢于、需要等. 二、形式变化二、形式变化1) 情态动词没有人称和数的变化情态动词没有人称和数的变化,

2、第三人称单数第三人称单数 的现在时也无变化的现在时也无变化.2) 有些情态动词有过去式有些情态动词有过去式, 有的过去式和它的原有的过去式和它的原型相同型相同. a. 有过去式的有有过去式的有: can could may might will would shall should dare dared need needed have to had tob. 过去式不变的有过去式不变的有: must must (或或had to) ought to ought to 三、否定式三、否定式shall not shant will not wont can not cant must not m

3、ustnt should not shouldntought not to would not wouldnt could not couldnt dare not darent need not neednt一、几个否定式的含义一、几个否定式的含义:Cant May not Mustnt Neednt Darent 二、几个委婉请求的答语二、几个委婉请求的答语:1. Could you lend me your pen? Yes, I _.2. Might I ask you a question? Yes, you _.3. Would you do me a favor? Of cour

4、se, I _.不能不能; 不会不会; 不可能不可能可能不可能不不许不许; 不该不该; 不可以不可以不必不必不敢不敢canmaywill三、几个一般疑问句的答语三、几个一般疑问句的答语:1. May I come in? Yes, you _. (No, you _.)2. Must I do it now? Yes, you _. (No, you _.)3. Need I type this letter now? Yes, you _. (No, you _.)maycant/mustntmustneedntmust/have toneednt四、四、can 和和 be able to:

5、*情态动词里能用来表示情态动词里能用来表示”能力能力”的只有的只有_ (现在现在)和和_ (过去过去); *_ 用来表示这一含义时可用各种时态用来表示这一含义时可用各种时态;*be able to用于过去时有特定的含义用于过去时有特定的含义, 相当于相当于 _ to do sth或或_ in doing sth;1. A blind man _ judge colors.2. He _ swim like a fish when he was young.3. Finally he _ marry the girl he loved.cancouldbe able tomanaged succ

6、eededcant/isnt able tocould/was able towas able to五、五、will的几个值得注意的用法的几个值得注意的用法:1. My grandpa is over 80, and he will sit at the table looking at the old pictures for hours.2. Mom, Im trying hard but the window wont open. Can you come and have a look?常用于肯定式，常用于肯定式，表示表示“习惯、倾向性习惯、倾向性等等”，意为，意为“老是老是，总是，总

7、是”常用于否定式，表示常用于否定式，表示“功能丧失功能丧失”，意为意为“可能因为出毛病而无法可能因为出毛病而无法” 如：如：My car wont start.六、六、would是情态动词错选率很高的词是情态动词错选率很高的词:1. 凡是在现在或将来的时态里用凡是在现在或将来的时态里用will的的才能在过去的时态里用才能在过去的时态里用would。*My grandpa was over 80 and he _ sit at the table looking at the old pictures for hours.*I tried hard but my car _ start.2. 除

8、此之外除此之外would只能用于只能用于语虚拟语气语虚拟语气、委婉的请求（一般疑委婉的请求（一般疑问句）问句）和和would rather/prefer/like/love等搭配等搭配中。中。在情态动词用在情态动词用得最广的得最广的“表示推测和责备表示推测和责备”中不能使用中不能使用。*Would you please do me a favor?*I would have failed without your help.wouldwouldnt七、七、shall的几个值得注意的用法的几个值得注意的用法: 用于第用于第 人称人称 （I shall be thirty next year. )

9、, 表示表示_. 用于第一、三人称一般疑问句（用于第一、三人称一般疑问句（Shall I open the door? Shall he come in?)中表示中表示_。3. 用于第二、三人称陈述句（用于第二、三人称陈述句（He shall answer for it. You shall get a rise if you do well. You shall do as I tells you to.)中表示说话者的中表示说话者的_等，翻译为等，翻译为“一定会、必须、应该、要一定会、必须、应该、要”等。等。4.用于第三人称陈述句的条约、法令、规章等文件用于第三人称陈述句的条约、法令、规章

10、等文件 （Newspapers here shall not be taken out of the reading room. ）表示）表示_。征求对方意见征求对方意见义务或规定义务或规定意图、允诺、威胁、命令、决心、愿望意图、允诺、威胁、命令、决心、愿望将来将来,将会将会八、常用于推测的八、常用于推测的can, may和和must:1. A:Look, someone is coming. Who _ it be? B: It _ be the headmaster. A:It _ not be him. He has gone out. B: Then it _ be Mr Smith.

11、 He looks the headmaster very much.2. He is a man of few words, but _ be quite talkative at times.canmaycanmustcan总结总结cancan：表示推测时一般用于：表示推测时一般用于_和和_句，不用于句，不用于_句，如果用了则表示句，如果用了则表示“并非并非一贯如此的情形一贯如此的情形”，意为，意为_。否定否定 疑问疑问肯定肯定有时会、时而可能有时会、时而可能总结总结maymay：表示推测时一般用于：表示推测时一般用于_和和_句，不用于句，不用于_句。句。总结总结mustmust：表示推测

12、时一般只能用于：表示推测时一般只能用于_句。句。肯定肯定 否定否定疑问疑问肯定肯定特别注意：特别注意：情态动词表推测时情态动词表推测时can/could, may/mightcan/could, may/might并没并没有时间上的差别，有时间上的差别，此差别是体现在它们所带的此差别是体现在它们所带的谓语动词的形式上谓语动词的形式上。试比较：试比较：*He must/could/may/might be at home now/tomorrow.*He must/could/may/might be playing football now.*He must/could/may/might h

13、ave tried his best yesterday.*He must/could/may/might have been working for hours yesterday.以上以上4句分别是对什么时间的动作或状态进行的推测？句分别是对什么时间的动作或状态进行的推测？现在或将来现在或将来现在正发生现在正发生过去过去过去正发生过去正发生九、情态动词表推测和责备九、情态动词表推测和责备(后悔后悔)的不同含义的不同含义:1. a. He was absent yesterday. He could/may/ might have been ill. b. He was absent yes

14、terday, or he could/may/ might have given you a hand.2. a. He had only a little work to do and should have finished it by then, or he couldnt have been back home. b. Jack, where is your homework? You should have finished it yesterday.可能可能(推测推测)本可以本可以(委婉责备委婉责备)应该已经应该已经(推测推测)本应该本应该(责备责备)十、十、情态动词情态动词+完

15、成式表推测和责备完成式表推测和责备(后悔后悔)的含义小结的含义小结: 推测推测 责备责备/后悔后悔maycould have donemight must have doneshould have doneought toneednt have done可能已经可能已经/(过去过去)可能可能一定已经一定已经/(过去过去)一定一定应该已经应该已经/(过去过去)应该应该 本来可以本来可以(实际实际没有没有) 本来应该本来应该(实际实际没有没有)本来不必本来不必(实际有实际有)十一、可兼做行为动词的情态动词：十一、可兼做行为动词的情态动词：need 和和 dare 情态动词 (+动词原形)行为动词

16、.needdare 1.1.无人称和数的变化无人称和数的变化; 2.2.尤其用于：尤其用于：* *否定句及疑问句中否定句及疑问句中; ;* *在在if/whetherif/whether之后之后; ;* *或与或与hardlyhardly, , nevernever, , no oneno one, , nobodynobody连用连用; ; 3. 3.常以常以needntneednt 和和darentdarent 的形式出现的形式出现; ;4.dare4.dare有其过去时有其过去时dareddared. . 多用于肯定句多用于肯定句; need to do dare to doneed t

17、o be done need doing 判断正误判断正误: How dare you say such a thing? How dare you to say such a thing?He darent to speak English before such a crowd, dare he?He darent speak English before such a crowd, dare he?True or false?Nobody need to be afraid of catching the disease.Nobody need be afraid of catching the disease.These dishes needed be cleaned carefully.These dishes need to be cleaned carefully.These dishes need cl