情態(tài)動詞can, may, must, need解析區(qū)別練習ppt.ppt

1、情態(tài)動詞,can,may,must,need,(能),(可以),(需要),(必須),From Jasmine Kan,情態(tài)動詞,情態(tài)動詞后面 + 動詞原形,情態(tài)動詞沒有人稱和數(shù)的變化,1,can,I can not play basketball.,I need buy / bought a computer.,2,(能),need,(需要),She can / cans ride a horse.,Amy need / needs buy a book.,-,-,-,-,3,否定式構成是在情態(tài)動詞后面加 not,I can play / played basketball.,-,can,(能

2、),用法:, 表示能力 :,He can speak a little English.,Can you fly?, 表示請求或允許 :,Can I help you?, 表示猜測 :,That can not be our English teacher, because she has gone to Shanghai .,could也可表示請求，語氣委婉，主要用于疑問句， 不可用于肯定句，答語應用can,Could I come to see you tomorrow?,Yes, you can. （否定答語可用No, Im afraid not.）,注意,用法:,表示請求或允許 :,M

3、ay I go home，please?,(1)以may（表許可或請求）開頭的一般疑問句,肯定回答用may，否定回答用mustnt或cant. (2)在疑問句中不用于第二人稱, 表示可能性 :,You may be right.,No, you _,may,(可以),Yes, you may.,注意,might為may的過去式，但也可以代替may， 語氣較為婉轉客氣或更加不肯定。,You might be right.,might,mustnt / you cant.,試比較 :, You may not smoke here(不可以) 語氣輕, You cant smoke here（不能）

4、重, You mustnt smoke here（決不可）最重,cant,may not,mustnt,用法:,既可以做情態(tài)動詞, 也可以做實意動詞, 實意動詞 (need to do sth) :, 情態(tài)動詞 (need do sth) :,I need buy a big house.,need,(需要),He need drive me home.,Do I need to buy a big house ?,He needs to buy a big house.,Need I buy a big house ?,- Yes, you must. - No, you neednt /

5、dont have to. (不必要),- Yes, you do. - No, you dont.,用法:, 表示推測“肯定，一定” :, 表示義務、必要或命令 :,You must come early tomorrow,-Must I finish my homework first?,They must be at home. The light is on.,- Yes, you must. - No, you dont have to/ neednt.,must,(必須),注意,must開頭的疑問句，其否定回答通常用 dont have to 或neednt 。 而不用mustnt

6、,mustnt,(禁止), 否定時表示 “禁止” :,You mustnt smoke here.,用法:,Its eleven oclock . I have to go now . It was getting dark. He had to finish the work first .,I dont have to go now . He doesnt have to finish the work first.,have to,(必須),注意,have to 表示客觀因素 We are very glad at the party , but its 11 , so we have

7、to leave now . must 表示主觀因素 We must study hard to find a good job for ourselves .,must,(必須),have to, must 區(qū)別,My brother was very ill, so I call the doctor in the middle of the night. He said that they work hard.,You dont have to tell him about it.,You mustnt tell him about it.,你不一定要把此事告訴他。,你一定不要把這件事告

8、訴他 .,have to,must,had to,must,區(qū)別,Can I ? Yes, you can. No, you cant. May I ? Yes, you may. No, you cant / mustnt. Need I ? Yes, you must. No, you neednt. Do I need to ? Yes, you do. No, you dont. Must I ? Yes, you must. No, you neednt.,-,-,-,找伙伴,Exercises,1. Must we clean the house now? No, you_. ne

9、ednt B. may not C. mustnt D. cant 2. You return the book now. You can keep it next week if you like. A. cant B. mustnt C. neednt D. may not 3. Johnny, you play with the knife, you hurt yourself. A. wont.cant B. mustnt.may C. shouldnt, must D. cant.shouldnt 4. _I go back before lunch? No, I dont thin

10、k you_. A. Need.must B. Do.need to C. Must.have to D. May . ought to,A,C,B,C,5. The teacher_ do all the exercises, but a pupil_. A. neednt.must B. may not.must C. neednt.neednt D. cant.must 6. Must I finish this novel this morning ? No, you_. A. mustnt B. might not C. dont have to D. cant 7. The taxi _ only hold six passengers. It is full. You _ take the n