Unit15 The necklace grammar( 可能是 Kate 。 )( 绝对不是 Marry 。 )( 可能不是 Tommy 。 )Mum: Who is it?Jim: ( 一定是 Tom 。 )It must be Tom.It may be Kate.It can’t be MarryIt couldn’t be Tommy.mustcan / couldmay / mightPositive: must can may might couldNegative: can’t mayn’t mightn’t couldn’tQuestion: can may could might 2. It must have rained last night, _________?1. It must be nice to take a walk here, __________?1. must 表示推测时，其反意疑问句应根据动词的实际时态而变化。如： isn’t it didn’t itWe must have been met somewhere before.You must have seen her yesterday, didn’t you?2. Must have done 意为“一定做过”，表示对过去发生的事情进行肯定推测。如：1. 我们以前一定在哪里见过面。2. 你昨天一定看到她了，对不？ 1.can 表现在和将来 ,could 既可表过去 , 也可表现在或将来 .2.can/could 可与 not 连用 , 表示否定推测 , 也可用于疑问句中 .3.can / could 表推测时，其反间疑句也是根据动词的实际时态国以变化。如：你不可能当真的，对不地？You can’t be serious, are you?4. can / could have done ，意为“本来能够”，事实却相反 . 如： 你本来可以来早点的。You could have come earlier.1. may / might 的可能性最小，往往表示原因说话人对某事没把握2. May / might 可与 not 连用，表示否定推测，但 may 用于疑问句时中能表示请求允许。The teacher may not e serious.May I leave now?3. May / might have done, 表示对过去可能发生某事的推测。 如： 你在做这件事时也许注意到了什么。You may have noticed something while you were doing this.1. I am not sure whether he will come or not. He must come tonight.2. He mustn’t be an American because he can’t speak English at all.3. I tried to call him at the office, but there is no reply. He can be at home.4. --- Is John coming by train? --- He should, but he ____ not. He likes driving his car. (NMET 2002) a. must b. can c. need ...
