情态动词的用法二新课标人教版介绍.pptVIP

情态动词（二）;情态动词表猜测;Should/ ought to　应该（而ought to 语气更强）;Must/ have to Must 必须，侧重说话人的主观看法 Have to (有多种时态）侧重于客观上的需要，含有 “不得不”的意思 I must go now.(主观看法） I have to go now.(客观需要） ;2)---Must I come?;can 客观上能够 be able to 更侧重于“克服一定困难”“经过一定努力”“有能力”干某事 We shall be able to finish the work next week. I haven’t been able to find the book.;Need 需要 1)情态动词　need do sth 实义动词　need to do sth (A)----Need I come? (B)---Do I need to come? ----Yes, ________. --- Yes,_________. ----No,_________. ---No, __________. 否定：你不需要待在床上。 You needn’t remain in bed. You don’t need to remain in bed. 2) need doing… = need to be done (某事需要被做） 花需要浇水。;Need I do …? Yes, you must. No, you needn’t. ; should ought to;1）用于第一人称表将来。I shall go to work after I have finished school. 2）用于一、三人称疑问句、表征求对方意见或向对方请求。 Shall he come in? — Come in, please. 3）用于二、三人称，表示保证、承诺、威胁、警告。 You shall be punished if you insist on doing it this way.;1）预测、可能。They should be here by now. 2）说话人的感情。如惊奇、愤怒、失望等、“竟然” You can’t imagine that well-behaved gentleman should be so rude to a lady.; must表主观意志，而have to表由于客观因素不得不做完成的事情。 Must没有过去式，除在间接引语中可表示过去的时间。在直接引语中表示过去的时间用had to代替。 I told her that she must give up smoking. She said, “We had to get everything ready that night.”;needn’t 对其它情态动词的回答: --Shall I tell John about it? --No, you __________. --Must we do it now? --No, you __________. ;Could I borrow your dictionary?(委婉) ---- Yes，you can/may. Sure. Go ahead. Please yourself. May I take this seat?(第一人称疑问句) Yes, you may. No, you mustn’t.;Must +have done 表示对过去已经发生的行为进行推测，意为“想必/准是/??定作了某事”。;can/could+have done表示对过去的行为的怀疑和不肯定，通常用在否定句和疑问句中。;may/might+have done表示对过去已发生行为的推测，意为“也许/或许已经…”。一般只用于肯定句和否定句中，不用与疑问句。might比may更委婉、含蓄和不肯定。 ;could(不用can)+have done,在肯定句中表示“本来能够…而没能…”，具有婉转的批评和责备之意。;should/ought to+have done用于肯定句时，表示“本该做某事而实际上没做”，用于否