2019-2020学年外研版高中英语选修8优化教案:Module 6 Section Ⅲ Grammar — 情态动词
2019-2020学年外研版高中英语选修8优化教案:Module  6  Section Ⅲ  Grammar — 情态动词第3页

  (2)must表示"一定,非得;偏要",语气强烈。

  If you must ask for a leave today, you must give out your reason.

  如果今天你非要请假的话,你就得说出理由。

  [即时演练2]

  (1)单句语法填空

  ①Listen, he must be_reading (read) English.

  ②Since nobody gave him any help, he must have_done (do) the research on his own.

  ③It is important to know about the cultural differences that may cause (cause) problems.

  (2)选词填空(must/may/might/can/can't)

  ①If you must go, at least wait until the storm is over.

  ②We enjoy good weather in January, but sometimes it can be terribly cold.

  ③I haven't decided where I'm going for my holiday. I may/might go to France.

  ④The story he told can't be true, because it is not reasonable.

  ⑤Can they finish this before the deadline?

  二、should, could, would的用法

  (一)could的用法

  1.表示过去一般的能力(即想做某事就随时可以做某事的能力)。

  Could you speak English then?

  那时候你会说英语吗?

  [名师点津] 若表示过去的特定能力(即在过去特定场合做某事的能力),则不能用could,而用was (were) able to do sth.或用managed to do sth.或用succeeded in doing sth.等。

  The fire was very big but everyone was able to escape from the building.

  火势很凶猛,但大家都逃了出来。

  2.could表示推测,表示某事有可能发生或可能是事实。在肯定句中没有must那么有把握;在否定句中没有can't那么有把握。

  He couldn't be a bad man.

  他不大可能是坏人。

  He could have gone home.

   他可能已回家了。

  3.比较委婉客气地提出问题或陈述看法。

  Could you drive me to the station?

  你可以开车送我去车站吗?

  We could take the train or alternatively go by car.

我们可以坐火车去,也可以坐汽车去。