必修三英语unit1情态动词的用法.ppt

2021/2/21 * shall: 1.Shall用于第一、第三人称疑问句中,表示说话人征求对方的意见、向对方请示或提供帮助 。 1.Shall we begin our lesson? 2.When shall he be allowed to leave hospital? 3.Shall I carry this bag for you? 2021/2/21 * shall: 2.Shall用于第二、第三人称,表示说话人给对方命令、警告、允诺或威胁。 You shall fail if you don‘t work harder.  He shall be punished according to the rule. He shall have the book when I finish it. 警告 威胁 允诺 2021/2/21 * should 1. Young people should respect old people. should 表“义务,建议”。 2. It’s five o’clock. John should be at home now. 表推测,按道理应当。译为“理应,估计 We have prepared a fridge of good and drinks. That should be enough for the party. 2021/2/21 * 3.表示 “竟然” It’s a pity that he should be so rude to a lady. 2021/2/21 * 情态动词 用 法 shall 征求对方意见 (第一, 三人称) 表示命令,警告, 威胁或允诺 should / ought to 表示劝告,建议,命令或责任 “应该, 必须” 表示推测, “理应, 估计, 大概” should 还可表示“竟然” must 表“必须” don’t have to don’t need to needn't — Must we hand in our exercisebooks today? — Yes,you must/ No,you don’t have to 2. 1. 不必须 mustn’t 禁止 2021/2/21 * 表“推测”时: 肯: must be +表语 (一定…） 否: can’t (不可能…) e.g. That can’t be Mary. She is in New York. 3. have to “不得不”,表客观需要 2021/2/21 * 情态动词 含义 否定式 注意点 must 表必要 “必须” needn’t “不必” ( 区别 have to) 有时表“偏要” 表推测 “一定” can’t “不可能” 只能用于肯定句,不能用于否定、疑问句 You ___ buy a gift, but you can if you want to. must B. mustn’t C. have to D. don’t have to 2. When I was young, I was told that I ______ play with fire. A. wouldn't B. needn't C. mustn't D. daren't 3. - May I smoke here ? - If you __, choose a seat in the smoking area. A. should?? B. could?? C. may?? D. must 情态动词表推测 可能性的强弱层次 must should/ought to can/could may/might ＞ ＞ ＞ 1. That ______ be Ann’s husband, for I am sure that he doesn’t wear glasses. A. can’t B. may no