Unit 2 Let’s celebrate! 语法课件-2025-2026学年高中英语外研版必修第二册

The Perfect Usages of Modal Verbs Instructor: XXXX Email: XXX@qq.com Note: microlecture on 202X.XX.XX modal verb expression of feeling and attitudes non-dependent verb no tense changes Lead-in Types 1 must have done 2 can/could have done 3 may/might have done 4 should/ought to have done 5 needn’t have done present tense: modal verb+ verb speculation on the current situation A perfect tense: modal verb + have+past participle speculation on the current situation B present and perfect tense (modal verb) Lead-in present tense: modal verb+ verb speculation on the current situation A perfect tense: modal verb + have+past participle speculation on the current situation B present and perfect tense (modal verb) Lead-in modal verb + have+past participle 1 must have done must have done 用于肯定句，表示对过去肯定的猜测，表示"过去一定做过某事"，是很有把握的推测。其否定形式为 can ' t / couldn ' t have done 。 I must have seen you somewhere, but I can ' t recollect your name. 我一定在哪个地方见过你，可我想不起你的名字了。 The room is in a terrible mess; it can ' t have been cleaned. 房间里乱七八糟，一定没打扫过。 can/could have done 是对过去本来能做而未做的事感到惋惜和遗憾，表示“可能、本来能够做什么 ”。 The output could have been increased by 15%. 产量本可以提高15%的。 2 can/could have done may/might have done对过去情况的一种不太有把握的推测，表示“过去可能已经做了某事”； 其否定形式表示为“过去可能还可没有做某事”。 He may have had some training in Chinese Kungfu. 他可能学过一点中国功夫。 3 may/might have done should/ought to have done意为"本应该……"，表示本应该做某事，而实际没有做，含有责备或遗憾的语气。其否定形式为 should not have done 或 ought not to have done "本不该做某事"，表示某种行为不该发生但却发生了。 They ought to have completed their work much earlier. You shouldn' t have left your son alone at home. 4 should/ought to have done needn’t have done 指没必要做某事,实际上却做了，表示"本不必做"。 You needn' t have woken me up ; I don ' t have to work today. 你根本不必叫醒我，今天我不用上班。 5 needn’t have done Summary See you later! $