情态动词 中小学语法ppt课件.ppt
Summer is coming.,A big suntell me some words about it.,hot,sunny,holiday,swim,Ice-cream,skirt,fire,What shall we do if a fire happens?,Discussion,must or mustnt,4. Take the left.乘电梯逃离。,5. Jump out of the tall building.跳楼.,1.Use wet quilt or cloth to block the door.用湿的被褥或衣服堵住门。,2.To make a quick departure， run away.当机立断，迅速逃离。,3.Call 114.,6.putting it out with a fire-extinguisher用灭火器灭火。,7.Find some extra way to get themselves out.多掌握几条逃生路线。,must,mustnt,must,must,must,mustnt,mustnt,情态动词,情态动词有时又叫情态助动词。情态动词本身虽有一定词义，但不能独立用作谓语、也没有人称和数的变化，其后一定要跟随动词原形，共同构成复合谓语。,May I?,May I come in?,May I use your pen?,He must take some medicine.,Mustnt swim,Mustnt touch,常用的情态动词有哪些？,Can能，会-cant 不会Could-couldnt/be able toMay可能，或许-may notMight可能（更加委婉）-might notMust必须-mustntHave to不得不-dont have toNeed需要-neednt,Lets do it,I( )dance.,I ( )go to Harford one day.,You( )turn off the lightwhen you leave the room,1.Tommy can drive the carRobot can do many things.2.I could send cards before having the computer lessons.(表示过去的一种能力)Could I sit here?(用于一般疑问句中，语气更加温婉)3.be able to可用于各种时态之中 I will be able to live on the moon.She was able to (could) finish the homework.,I was able to Disney last month.I was able to swim across the Ganjiang river last summer.（表示有能力做，并且成功了）She could fly over the South Pole.(不一定成功),1.can/could/be able to?,1.can能，会2.could比can更为委婉的语气；表示过去曾有过的能力；3. was (were) able to与could的区别是表示不但有能力，而且成功的做了某事。,He may be sick.(生病的可能性较大) He might be sick.(生病的可能性较小),(2)may/mightMight比may更委婉,注意： may引导的疑问句，肯定回答用：Yes, you may. 否定回答用： No, you mustnt. (No, you cant或No, you had better not.)表示“千万不要”，“不可 以”，“禁止”的意思。,3.must, have tomust “一定，必须”； have to不得不”。如果用于过去时或将来时 ，要用have to来代替，但must可用于间接引语，表示过去的必要和义务。You must stop smoking. 你必须把烟戒掉。(强调主观意志)I have to stop the car and wait for the policeman. 我不得不停车等那个警察。(强调客观)Must提问 否定回答只能用neednt或者dont have to,I must study hard.,i have to study hard.,骂你没妈,Must提问-neednt回答（dont have to）May提问-mustnt回答（cant）,4.needA 作为情态动词使用：need没有时态与人称的变化，并且多在否定句，疑问句和条件句中使用，含义为“需要，必须”。You need not hand in the exercise today.你不必今天交作业。Need we find time to go into the question?要不要我们找时间把这个问题深入研究一下?,5、情态动词表示推测或判断的用法,It must have rained last night.(对过去的猜测),情态动词练习（1）1.We_forherbecauseshenevercame.A.needntwaitB.shouldnthavewaitedC.mustntwaitD.mustnthavewaited2.Janny_havekeptherword.Iwonderwhyshechangedhermind.A.mustB.shouldC.needD.would3.Itsnearlysevenoclock.Jack_behereatanymoment.A.mustB.needC.shouldD.can4.WhencanIcomeforthephotos?Ineedthemtomorrowafternoon.They_bereadyby12:00.A.canB.shouldC.mightD.need5Bequick!They_forusatthechurchgaterightnow.A.mustwaitB.musthavewaited C.mustbewaitingD.oughttowait,6.should， wouldshould表示应该做某事或承担责任、义务；例如：You should work harder and pass the exam. (表示应该)你应该更加努力，通过考试。,Had better最好+V.原型Youd better put on your coat.否定形式：had better not最好不要Youd better not eat so much ice-cream.,
