1、情态动词情态动词 目录 CONTENT 01 情态动词的定义情态动词的定义 02 情态动词的选择情态动词的选择 1.You neednt try it if you dont want to.2.The man can speak two foreign languages.3.The poor boy had to face the problem bravely.情态动词情态动词_独立作谓语，只能和独立作谓语，只能和_一起构成谓语，一起构成谓语，没有数的变化，具有助动词功能。没有数的变化，具有助动词功能。1.情态动词的定义情态动词的定义 不能不能 情态情态动词动词(Modal verb)情
2、感情感&态度态度 动词原形动词原形 2.情态动词的选择情态动词的选择 情态动词情态动词 can may shall must will need dare could might should/would/1.部分情态动词有时态变化（一般现在时/一般过去时）；2.情态动词无人称数的变化，除be able to,have to以外；be able to had better ought to have to can&could 2.情态动词的选择情态动词的选择 1表示能力能力，译为“能够.”Nobody can stop the development of science.2.表示请求建议请求
3、建议，用could比can语气更委婉(could在此并非表示过去式)，回答用原形 Could you please wait me a moment,Jenny?Yes,I can.3.(用于否定句、疑问句或感叹句中)表示猜测猜测(通常否定通常否定)或惊诧惊诧 How can/could you be here?你怎么会在这儿？She couldnt/cant be so stupid to do that.她不可能蠢到去做那种事吧。can/could与与be able to的区别的区别 2.情态动词的选择情态动词的选择 1.The man can/could speak two foreig
4、n languages.2.Yesterday I was able to get home before the heavy rain.can/could表示_，而be able to通常表示通过努力达成的_;can/could 主要是一般现在、一般过去时,而be able to有较为丰富的时态变化。习惯性具备的能力习惯性具备的能力 一次性的能力一次性的能力 may&might 2.情态动词的选择情态动词的选择 1.表示请求或请求或允许允许，译为“可以”。might语气较委婉(但并非表示过去)。I wonder if I might ask you a favor?You may tell
5、him this.2.表示推测推测,译为“可能”。might比may所表示的可能性更小。That may/might not be true.3.may/might well(很可能);may/might as well(不妨，还是.为好);You may well be right.你很可能是对的。Its freezing cold outside.We may as well stay at home.4.may放在句首，表示祝愿祝愿。May God bless you!shall&should&ought to 2.情态动词的选择情态动词的选择 Shall 1.shall用于第一第一人称
6、时人称时，可表示征求对方意见征求对方意见，译为“要不要.”(通常为疑问句)；或者表示将要发生的事将要发生的事，译为“将要.”(通常为肯定句)。Shall we begin our class?(表示征求意见)I shall be in Shanghai this time next week.(表示将来动作)2.shall用于第二第二、三人称三人称时时,表示命令规定命令规定(通常为肯定句)。译为“应该”。You shall go to school on time.shall&should&ought to 2.情态动词的选择情态动词的选择 Should/Ought to 1.表示义务或责任义
7、务或责任,译为为“应该”。We should/ought to learn from each other.2.表示建议或劝告建议或劝告，译为为“可以，应该”。You should/ought to try your best to better your performance.3.表示推断推断,译为”应该”,“可能”,“按道理会”。They should/ought to be there by now.4.should表示意外或惊讶表示意外或惊讶，译为“竟然”。Its strange that he should come so late.must&have to 2.情态动词的选择情态
8、动词的选择 Must 1.must表示“必须”(侧重于主观意愿主观意愿);mustnt表示“禁止”。Must I do my homework now?You mustnt smoke here.2.must表示推测推测，译为“准是，一定是”(只用于肯定句)。若用于否定句或疑问句，则用cant(一定不是)。That cant be the only way.There must be other ways of solving the problem.Have to 表示客观上的需要，强调被迫性强调被迫性，有“不得不”的含义。Sorry,I have to leave now.will&wou
9、ld 2.情态动词的选择情态动词的选择 1.表示意愿，译为“愿意愿意”。will指现在的意愿，would指过去的意愿。I will read the letter for you,if you want.He asked if I would show him the way.2.表示委婉语气委婉语气，译为“好吗？”。would较will而言更加委婉。Will/Would you please pass me the salt?Would you like a cup of tea?3.表示习惯或倾向习惯或倾向，译为“一般，总会”。will表示现在，would表示过去。He would alw
10、ays complain if he got the opportunity.Wherever he goes,he will take an umbrella with him.need 2.情态动词的选择情态动词的选择 1.need用作情态动词，表示“需要”(无时态与人称的变化)。I need your help.She need not any help.(否定时否定时，直接在情态动词后直接在情态动词后+not)2.need用作实义动词，通常为“need to do sth”结构或“need+n”(有时态与人称的变化)。need to be done=need V-ing Lily ne
11、eds more money to pay for that book.(时态变化时态变化)Lily needed more money to pay for that book at that time.(人称数的变化人称数的变化)Lily doesnt need any more money to pay for that book.(否定否定，添加助动词添加助动词)dare 2.情态动词的选择情态动词的选择 1.作情态动词，译为“敢”，通常只用于否定句、疑问句以及if或whether之后，一般不用于肯定句。(无人称变化，有过去式dared)Dare you tell her the tr
12、uth?I darent ask her this question.2.作实义动词，译为“敢于”，通常为“dare to do sth”(有人称与时态的变化）She dares to go alone.She doesnt dare to go alone.She didnt dare to go alone.情态动词表推测情态动词表推测 2.情态动词的选择情态动词的选择“情态动词have过去分词”表示对过去动作或状态的推测、假设过去动作或状态的推测、假设 （1）must have done“（2）cant/couldnt have done“过去不可能做了某事”（3）may/might h
13、ave done“过去可能做了某事”（4）neednt have done“过去本来没有必要做而做了某事”（5）need have done “过去本需要做某事而实际未做”（6）should/ought to have done“过去本来应该做某事而没有做”（7）shouldnt/oughtnt to have done“过去本来不应该做某事而做了”情态动词表推测情态动词表推测 2.情态动词的选择情态动词的选择 1.He is right.2.He must be right.3.He will be right.4.He would be right.5.He ought to be rig
14、ht.6.He should be right.7.He may be right.8.He could be right.9.He might be right.certain almost certain uncertain 1.Tom likes his job because he _ enjoy the beauty of nature.A.can B.must C.should D.be supposed to 2.-Do you have any plans for this Sunday?-Im not sure.I _ go to the countryside to see my grandma.A.can B.must C.may D.need 3.Nowadays,all passengers _ go through safty check before take a train.A.can B.may C.must D.will 4.-Must I clean the classroom now?-No,you _.5.The woman _ be our teacher.She has gone to Canada.课堂小练课堂小练 C A C neednt cant Thank you!