高一英语获奖课件unit14grammar.ppt

Grammar,Review,1. Had better,最好最做某事,(1) 肯定句: youd better do sth.,Youd better leave here now.,(2) 否定句: youd better not do sth.,Youd better not leave here now.,(3) 疑问句: had you better do sth.?,Had you better leave here now?,(4) 反意疑问句:,Youd better not leave here now, had you?,Youd better leave here now, hadnt you?,2. 情态动词ought to 与should 的用法,Ought to 和 should都可以表示”应该”的意思,Ought to 表示“按理应该”，侧重反映客观的情况。 Should 表说话者的主观看法。,I think you _ call on Mary next week. You have seen him for three times, so you _ know him.,should,ought to,(2) 否定句： ought not to 与 should not 意思基本相同,(3) Ought to have done = should have done 应该做某事但实 际上未做,我原本应该抓住这个当经理的机会，但是我错过了。,I should have / ought to have seized the opportunity to be a manager, but I missed it.,3. 更多情态动词：,Must I come here early? Yes, No,you must.,you neednt / dont have to.,(2) Must have done 对已发生事的肯定推测 shouldnt have done 对已发生事的否定推测,他去年一定去过美国。,He must have been to America last year.,He must have been to America last year.,(3) Would have done 表现实中结果没发生的事,没有你的话我就死了。,Without you I would have died.,(4) neednt have done,原本没必要做某事,你原本不必起那么早，但是我们实在需要你帮忙。,You neednt have got up so early but we really need your help.,Model verbs (),must,have to,have got to,must not / mustnt,dont have to,havent got to / hasnt got to,Must sb?,Do / Does sb. have to ?,Have / Has sb. to ?,（必须、应当）,（必须、不得不）,表示义务、命令或必要，后面接不还to的动词学定式。 Soldiers must obey orders. We must keep our word. 2. must 用在否定句结构中表示“不允许、禁止” He must not leave his room. You mustnt smoke in the office. 3. must用在一般疑问句中，肯定回答用must，否定回答用neednt 或dont have to Must I hand it in before five? No, you _. Yes, you _.,you neednt. / dont have to,you must,must的用法,have to和have got to 的用法,have to 由have + to组成。因此具有have的各种时态。 He is an invalid and has to have a nurse. She knew what she had to do. I shall have to reconsider my position. He is always having to exercise judement. 2. 在口语中，have got to 也可以表示义务和需要， 与have to 基本同义。 He has got to go right now. He hasnt got to go just yet.,must和have to的区别,含义不同： must 表示说话人的主观思想，强调个人意志和主观的决心。 have to侧重于客观上的必要，强调客观条件作用的结果。 You must do it now. I have to go now.,3. 否定含义不同 在否定句中, have to表示不需要，must则表示不允许。 You dont have to go there. You mustnt go there.,2. 适用时态不同 must 只能用于一般现在时和一般过去时，（在间接引语中） have to 可用于更多的场合。 She said she must do well in her English.,Exercises,Dont be late again. You _ be here on time. A. may B. can C. must D. neednt You _ do it even if you dont want to. A. cant B. mustnt C. neednt D. have to 3. Must I take a bus? No, you _. You can walk from here. A. mustnt B. dont C. don t have to D. had better not to 4. It is rather cold here. Shall we light a fire? No, we _, because things here are easy to catch fire. A. wont B. cant C. mustnt D. neednt,你 去睡一觉。 2. 你 邀请他。 3. 你 照你父母的话办。 4. 你 抽这么多的烟。,Youd better get some sleep.,Youd better not invite him.,You should do what your parents tell you.,You oughtnt to smoke so much.,最好