情态动词 序号知识要点已掌握需巩固1can 在肯定句中“有时”的推测用法。It is usually warm in my hometown in March, but it can be rather cold sometimes.2区分：could 与 were / was able to do 3疑问句中“推测”只能用 can/ could 4区分：May I …? 与 Shall I …?5区分：may well do 与 may（might） as well do / have done6may 表祝愿。 May you succeed!=Wish you success!7Could I …? Might I …? 回答应是： Yes, you can / may.8must 还可以表示“偏要”“必然”的用法。The car must break down just when we were about to set off. All men must die.9must 表示肯定的“推测”。(must 表推测时只用于肯定句。)10mustn’t 表示“千万不能”。11shall 用于一、三人称疑问句中表示征求第二人称的意见shall 用于二、三人称陈述句中表示警告，命令，允诺，规定12should ① 应该=ought to ② 竟然。 should do / should have done③ 表推测，“按理应该”=ought to ④if 虚拟从句中： If sb should do=Should sb do ⑤ 用于“建议、命令等”虚拟结构中或 it is adj/n that 引导的主语从句中⑥ 与“I ”连用，表示委婉语气。You are mistaken, I should say. 13will/ would 表示意愿、倾向性、现在（过去）的习惯性动作。14dare 和 need 的用法①行为动词 ②情态动词（dare 的过去式为 dared）15对过去的“推测”： ① can/ could have done (用于疑问句) ② can’t/ couldn’t have done （用于否定句）③ may/ might have done （用于肯定句） 用于肯定句时表示“可能已经做了某事” ,在没有“may/might”的情况下，可用“could ”替代。④ may not / might not have done （用于否定句）⑤ must have done (用于肯定句)16情态动词表“推测”时的反意疑问句。① He must be playing football on the playground, isn’t he?②He must have been told the news, hasn’t he?③He can’t be at home, is he?④His book must have been published last month, wasn’t it?17情态动词表示对过去的“虚拟”的用法。would/ could/ might have done may/ might as well have done would like/love to have done had better have done18区分：needn’t have done 本不必要做某事（事实上做了）与 didn’t need to do 没有必要做某事（事实上没做）19区分：if you must… / if you will… / if you should …/ if you are to do sth
