Unit 8-9 Unit8 It must belong to Carla.1. 如用must ,may, might, can 和could 来表示推测(1) 在肯定句中一般用must(一定)， may(可能，也)， might/could(可能/也)。 He must /may/ might/ could know the answer to this question.他一定/可能知道这个问题的答案。It is cold in the room. They must have turned off the heating.屋里很冷，他们肯定把暖气关了。否定句中用can’t/ couldn’t(不可能) ， may not/ might not (可能不，也不)。 The man can’t/ couldn’t be the headmaster. The headmaster has gone to America. 那个男人不可能是校长。校长去美国了。 He may/ might not know the scientist. 他也不认识那位科学家。温馨提示：might, could 并非may, can 的过去式， 而表示语气较为委婉或可能性较小。2. 情态动词表推测的三种时态(1) 对将来情况的推测， 用“情态动词+ 动词原形”。 如： She must / may/ might/ could arrive before five.(2) 对现在或一般情况的推测， 用“情态动词+ be”, “情态动词+ be doing” 或“情态动词+ 动词原形”。 He must / may/ might/ could be listening to the radio now. He can’t/ couldn’t / may not/ might not be at home at this time.对过去情况的推测， 用“情态动词+ have+ 过去分词”， The ground is wet, It must / may/ might/ could have rained last night.温馨提示： 情态动词should/ ought to 表推测时， 意为“按说应该……”，但与“have+ 过去分词”连用时， 意为“本应该做某事却没做”。 It’s seven o’clock, Jack should/ ought to be here at any moment. She should ha |
