might，may，must，can.might，may，must表示的可能性程度由弱变强
must表示"；一定"；， can则一般用于疑问句或否定句中.
例如:
They must be talking about us on the radio right now.
此刻，他们一定在电台里谈论我们的情况.
2、She may have missed her train.
她可能没有赶上火车.
3、I don'；t know why he is late，he might have had an accident.
我不知道他为何迟到，可能遇上了事故.
4、Where can John have put the matches He can'；t have thrown them away.
约翰会把火柴放在哪儿呢 他不可能把火柴扔掉的.
5、That can'；t be the postman，it'；s only seven o'；clock.
才七点钟，不可能是邮递员.
表示推测的情态动词后的动词不定式可用完成式，进行式和一般式三种.用完成式表示对过去情况的推测.
例如:
Her father thought that she must have met a fairy.
她父亲认为她一定碰上了仙女.
They must have studied English for years.
他们学习英语肯定有几年了.
You may have left your glasses at the office.
你可能把眼镜忘在办公室了.
用进行式则表示对正在发生的动作的推测.
例如:
He might be reading a newspaper now.
他可能正在看报纸.
He can'；t be working at this hour.
这个时候他肯定不会在工作.
Mary must have some problem ，she keeps crying.
玛丽不停地哭，一定有了麻烦.
I saw that the camel must be blind in the right eye.
我知道这只骆驼右眼肯定瞎了.
Our team must win the game.
=I'；m sure that our team will win the game.我们队肯定能赢这场比赛.
It might rain this evening.
=It'；s possi- ble that it will rain this evening.今天傍晚天可能要下雨.
情态动词语气强弱排序初中
语气强烈（从左往右强烈程度依次减弱）：must 、can/could、shall/should、may/might、will/would
