2020高中英语 情态动词（Modal Verbs）教案 外研版必修2

情态动词（Modal Verbs）一 概念和特征表示说话人对某一动作或是状态的态度的动词。情态动词具有一定的词义，但不能独立作谓语，要和后面的动词原形一起作谓语，它没有人称和数的变化，具有助动词的作用，即用来构成否定句、疑问句及用于简单回答。二 类型1. 只用作情态动词的：must cancould maymight ought to2. 既可作情态动词也可作实义动词的： need dare3可作情态动词也可作助动词的： shall should will would4具有情态动词特征的动词短语：have to used to would rather had better三 用法1 CanCould. 表示能力，相当于be able to。Can you speak English？He could swim when he was 5Can 只能用于一般现在时和一般过去式，而be able to可用于各种时态。She has been able to play the piano for 3 years.表示征求意见，许可，could比can的语气要委婉，相当于may 。Can I smoke here？ Yes，you can.No，you cant.She asked whether she could smoke here.You can go with us if you like. 表示推测，can比could可能性大, 用于肯定句、否定句、疑问句均可。Accidents can happen on such rainy days.It cant be true.Cancould V 原形表示对现在的状态特征推测Cancould be doing表示对正在进行的动作的推测Cancould have done 表示对过去的推测He cant be at home now.He can be studying now.He could have gone to school. Its Sunday.但是情态动词表示推测时其反义疑问句应根据动词的实际事态而变化。. could have done 本能够，本可以You could have borrowed my car. I wasnt using it.You could have come earlier. 表示说话人的惊异、怀疑、不相信的态度（主要用于否定句、疑问句和感叹句中）Can he be working till so late?How can you be so careless!2. May Might. 表示征求意见，请求和许可。May I smoke here? Yes , you may. No , you mustntd better not cant.You may smoke. 表示推测，may可能性比might大，不如can语气强烈。可能也许，通常用于肯定句中。maymightv 原形表示对现在的状态特征推测maymightbe doing表示对正在进行的动作的推测maymighthave done 表示对过去的推测At present, there may be some problems.They might have lots of work to do now but Im not sure.This might be done by Tom.Lets speed up. They may be waiting for us. 表示祝愿，用于倒装句。May主语动词原形。May you succeed！May he live to 100 years!May you have a good life！. maymight as wellV原形 “最好” “不妨”“还是的好”Its too late. You might as well not go.3. Must 表示说话人主观看法及强烈劝告“一定要必须”同have to,只用于现在或将来，但是have to表示客观条件环境迫使必须，可用于各种时态。mustnt 表示禁止，用以告诉别人不要做什么。dont have to和neednt都是不必没有必要用以回答must提问的疑问句。You must have a passport if you want to go aboard.You can go out with your friend but you must come back before 11 at night.I cant see clearly so I have to wear glasses.Must I do it now? Yes, you must. No, you needntdont have to. 表示推测，通常用于肯定句中，“一定”，很有把握，语气最强烈。其否定形式为cantcouldntMustV 原形表示对现在的状态特征推测Mustbe doing表示对正在进行的动作的推测Musthave done 表示对过去的推测He must be ill. I can see it from his face.Something must be burning. I can smell it.Someone must have entered this room yesterday, for my books have been moved. 表示偏要、固执He must come and ask her questions when she was busy.As I was about to start to work, the telephone must phone.4. Need表示“需要”或“必须”，作为情态动词时没有人称和数的变化，多用于疑问句和否定句中。 肯定句中用musthave toought toshould.You neednt explain.Need I take money? Yes, you must.No, you neednt.作为实义动词时有人称和数的变化，后面要跟带to的不定式。I need to go to Beijing this Sunday to attend a book fair.Do I need to leave my telephone number and address?neednt have done 表示本没有必要做某事。I neednt have bought so much wineonly three people came.5. Dare表示“敢”，作为情态动词时没有人称和数的变化，多用于疑问句和否定句中。过去式为dared.How dare you say “Im not fair”?I darent stay at home alone at night.You will be punished if you dare break the rule.作为实义动词时有人称和数的变化，后面要跟带to的不定式。This student doesnt dare to raise questions in class.Do you dare to drive a car on such a crowed street?I dare to swim in the river.6. Shall 用于第一、三人称疑问句中表示征求意见或请求。Shall we put off the sports meet until next month?Henry is waiting outside. Shall he come in now?用于二、三人称陈述句中表示说话人的命令、警告、威胁、决心或许诺等感情色彩。You shall get an answer tomorrow.If you do something wrong, you shall be punished.Nothing shall stop me.7. Should作为shall的过去式用于第一、三人称疑问句中表示征求意见或请求。Mr. Li asked if he should get his permit tomorrow.表示义务职责或是给别人提出建议“应该”。相当于ought to，但没有ought to语气强烈。ought to否定形式为ought not to或oughtnt to, 其一般疑问形式要将ought 放在主语前。I think todays children should learn to respect their elders.You ought to apologize to Joan.表示说话人的感情色彩，如惊奇、愤怒、失望等。“竟然”Im surprised they should refuse our invitation.表示很大的可能性，“应该”。They should arrive now.should have done 本应该做某事You should have invited me to your wedding, but you for got.8. WillWould表示请求，would语气更加委婉。Will you come this way, please?Would you open the window, please?表示意志、愿望、决心。I wont do that again.He said he would fight against AIDS.will 表示习惯性动作“总是”“惯于”；would表示过去经常习惯做同used to, used to的否定和疑问形式都有两种，分别借助于did和used。Fish will die out of water.The old man is strange. He will sit for hours without saying anything.You will regret if you lose such a good chance.After dinner, he would sit around Grandpa, listening to his stories.He used to be careless.He usednt to be careless. H