Modal-verb情态动词.pptVIP

He _________ (can, drive) the car. _____________( I must do) it that way? You _________ (need not finish) the homework today. 1. can and could (1)表示能力，能够，译为“能”，“会” can用于现在时，could用于过去时. 我能举起这块石头。 她说她能去。 这个男孩上学前能识字吗？ 与be able to的区别:  ① Can的主语是人或物,be able to的主语是人 She can/be able to sing the song in English. This machine can make you feel comfortable. ②时态 只用于现在式和过去式(could)。be able to可以用于各种时态。They will be able to tell you the news soon. 他很快就能告诉你消息了。 I haven’t been able to see the film. ③ could用于表示泛指过去的能力。表过去做某一具体动作, 用was/were able to=managed to do/succeeded in doing，表示经过一番努力, 终于能够完成某事。 1) I?could?read?when?I?was?four. 2) The first spread through the building very quickly, but luckily everyone was able to escape. 大火在楼里蔓延，幸好大家都及时撤离了。（在此不能用could ） 3) They didn’t want to come with us at first, but in the end we were able to persuade them. 起初他们不想与我们一起来，但是最后我们还是说服了他们。（在此不能用could） （2）表示推测，译为“可能”、“会”,往往用于否定句或疑问句, could语气比can委婉，含义较不确定。 Can it be true?(表推测) Could it be true?(表不大可能) 月不可能常圆。 The moon cannot always be at the full. ??我能借你的笔吗？ Could I borrow your pen? （3）表示许可，译为“可以”。(could可与can互换，不表过去时，Could可表委婉。) 明天你可以借用我的自行车。 You can borrow my bike tomorrow. 我可以插句话吗？ Could/Can I interrupt a moment? 固定习语 Cannot/couldn’t but 不能不, 不得不 我不能不感到遗憾。 I cannot help but be sorry. Cannot/couldn’t help (doing) 不禁, 忍不住她不禁哭起来。 She can’t help crying. May, Might (1)表示许可, 译为“可以”. may/might与can/could相比，前者较为正式，常用于正规文件；may/can与might/could相比，后者较为婉转，更有礼貌。在口语中常用can表示“许可”。 我可以在这抽烟吗？ May/Might/Can/Could I smoke here? 乘客不能在车内抽烟。 Passengers may/might not smoke in the car. （2）表推测，“可能”、“也许”，暗含不确定，等于possibly, perhaps, maybe。可用 于否定和肯定句，但不用于疑问句。Might 比may更不确定，不表过去时。 他也许马上就来。 He may/might come soon. 他也许正在做功课。 He might/may be doing his homework now. 固定搭配 may sb. do sth. 祝愿某人……, do是动词原型 祝你幸福。 May you be happy. May/might as well “不妨”、“还是…为好”等，用 might 比用 may 语气更委婉。 你还是把信给他为好。 You may/might as well give him the letter. Must和have to (1)表示义务和