情态动词学习五要素[课件]

1、情态动词学习五要素一、注意情态动词的推测用法推测性情态动词共有三个，其用法见表 情态动词 含义 适用句型 适用句型 可能，或许 肯定句 Must 一定，必须 肯定句 Can/could 可能，或许 否定句，疑问句 例1：-Are you coming to Jeffs party?-Im not sure. I _go to the concert instead.(NMET2000) A. mustB. would C. shouldD. might析：选D。Im not sure.的语境表明把握性不大，当然我去参加音乐演奏会的可能性就比较小了，故不用must应用might例 2：-_the

2、 news be true?No, it_be true.A. Can, cant B. May, cantC. May, may not D. Must, mustnt析： 选A。因为前半句是疑问句，后半句为否定句，两空都不能使用may/might 和must，应而用can和cant。二、了解情态动词的完成式用法（一）should /ought to have done本来应做而未做，表达遗憾感情色彩例1：I told Sally how to get there, but perhaps I _for her.(NMET94) had to write it out must have w

3、ritten it outC. should have written it outD. ought to write it out析：选C。分析语境可知，口头上告知Sally如何去那里是不够的，所以我本应书面告知，却有没书面告知之，显得应使用should /ought to have written表示遗憾之情。例2：I was really anxious about you, you_home without a word.(NMET2001) A. mustnt leave B. shouldnt have left C. couldnt have left D. neednt lea

4、ve 析: 选B。 由语境可知，我真的为你担心，所以你不应该一句话不说就离开家，但实际上你确实这么做了，显然应填shouldnt/ought to have left，表示责备。 （二）may/might have done可能已做must have done 一定已做cant have done不可能做例1：-Where is my pen? - I _it.(NMET88)A. might lose B. wouldnt have lost C. should have lost D. must have lost例2：The light in his room is still on,

5、so he _ to bed.A. mustnt have goneB. must have goneC. shouldnt have gone D. cant have gone析：选D。由于他房间里的灯还亮着推测，他不可能已经上床睡觉了，应填cant have gone 。（三）could have done指本来能做而实际未做，表达遗憾的感情色彩 You could at least have sent five cards.你至少可以寄5张明信片的。三、熟悉情态动词委婉用法： could, would, might等情态动词均有委婉用法，它们不是过去式而是表示语气委婉、客气、礼貌，常用

6、与疑问句，并多用于习惯表达， 如would you please, would you mind, would you like to等，might还可以用于肯定句表示推测，表示可能性小， might和could表示征求对方意见时，回答必须还成may, can.例1：-Could I borrow your dictionary?Yes, of course you_.A. mightB. will C. canD. should析：选C。该句用can的委婉表达式could 来征求对方意见，could 和might通用，但回答时必须还成can或may，因此该题不选A.例2：_you mind

7、my smoking here?A. ShouldB Could C. MightD. Would析：选D。征求对方意见我是否在这儿吸烟，语气理应委婉，所以应选委婉的表达方式would you mind来征求对方意见。四、弄清情态动词的异化现象有些情态用于疑问句进行回答时，出现了异化现象，此时回答在某个角度不能继续使用该情态动词， 而改用别的动词。 例1：-Must I start at once? No, you_.A. needntB. mustnt C. cantD. wont析：A。由语境可知该答句表示“不必”，而mustnt表示“不准、禁止”，不符合语境，显然应使用neednt表示“

8、不必”，但肯定句回答继续用must。例2：-Need I hand in my exercise book at once? Yes, you_.A. mustB. need C. canD. will析：选A。根据规定need用于一般疑问句作肯定回答应换成must,而作否定回答时，使用need的否定式neednt。五、掌握征求意见情态动词的回答不少情态动词可用于疑问句征求对方意见，但人称上有时有特殊要求，请看下表：情态动词 含义 征求意见使用人称 can/could 可以各种人称may/might 可以各种人称will/would 愿意第二人称shall 需要第一、第三人称must 必须各种人称need 需要各种人称 例1：-_I tell John about it? -No, you neednt. I have told him already.(NMET94)A. ShallB. Will C. CanD. May析：选A。从回答句“No, you neednt”的语境可知，问句征求对方意见，表