??用適當(dāng)?shù)那閼B(tài)動詞表示講話者對客觀事物的主觀看法，這就是情態(tài)動詞的推測性用法。常用來表示推測的情態(tài)動詞有 might，may，must，can。might，may，must表示的可能性程度由弱變強，must表示"一定"， can則一般用于疑問句或否定句中。例如：
    ??1．They must be talking about us on the radio right now．
    ? 此刻，他們一定在電臺里談?wù)撐覀兊那闆r。
    ??
    ??2．She may have missed her train．
    ? 她可能沒有趕上火車。
    ??3．I don't know why he is late，he might have had an accident．
    ? 我不知道他為何遲到，可能遇上了事故。
    ??4．Where can John have put the matches？ He can't have thrown them away．
    ? 約翰會把火柴放在哪兒呢？他不可能把火柴扔掉的。
    ??5．That can't be the postman，it's only seven o'clock．
    ? 才七點鐘，不可能是郵遞員。
    ??表示推測的情態(tài)動詞后的動詞不定式可用完成式、進行式和一般式三種。用完成式表示對過去情況的推測。例如：
    ??6．Her father thought that she must have met a fairy．
    ? 她父親認為她一定碰上了仙女。
    ??7．They must have studied English for years．
    ? 他們學(xué)習(xí)英語肯定有幾年了。
    ??8．You may have left your glasses at the office．
    ? 你可能把眼鏡忘在辦公室了。
    ??用進行式則表示對正在發(fā)生的動作的推測。例如：
    ??9．He might be reading a newspaper now．
    ? 他可能正在看報紙。
    ??10．He can't be working at this hour．
    ??這個時候他肯定不會在工作。
    ??推測性情態(tài)動詞后用不定式的一般式有兩種情況：如果不定式是狀態(tài)動詞，則表示對現(xiàn)在狀態(tài)的推測。如果不定式是動作動詞，則表示對將來動作的推測。例如：
    ??11．Mary must have some problem ，she keeps crying．
    ??瑪麗不停地哭，一定有了麻煩。
    ??12．I saw that the camel must be blind in the right eye．
    ??我知道這只駱駝右眼肯定瞎了。
    ??13．Our team must win the game．
    ??＝I'm sure that our team will win the game．
    ??我們隊肯定能贏這場比賽。
    ??14．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。
    ??上述表明，推測性情態(tài)動詞是以現(xiàn)在（講話時）為基礎(chǔ)，對過去、現(xiàn)在、將來的動作或狀態(tài)的推測。因此，在構(gòu)成陳述部分含有推測性情態(tài)動詞的反意疑問句時，要注意反意疑問句中動詞的不同形式。例如：
    ??15．The boy must have thought John was mad，didn't he？
    ??那孩子肯定以為約翰瘋了，是嗎？
    ??16．Our teacher must have looked through our papers，hasn't he？
    ??老師一定批完了我們的試卷，是嗎？
    ??17．She must be playing basketball，isn't she？
    ??她一定在打籃球，是嗎？
    選擇下列各句的正確答案。
    ??1．Hurry up，our teacher _____?for us at the school gate．
    ? A．must be waiting
    ? B．must wait
    ? C．might waiting
    ? D．can be waiting
    ??2．She doesn't answer the doorbell，she _____ be asleep．
    ? A．might to
    ? B．might
    ? C．must have
    ? D．should
    ??3．"What has happened to George ？""I don't know，he _____ lost．"
    ? A．can have got
    ? B．may have got
    ? C．might get
    ? D．could get
    ??4．Mr Li _____? be in Beijing because I saw him in town only a few minutes ago．
    ? A．needn't
    ? B．can't
    ? C．shouldn't
    ? D．mustn't
    ? 5．We can't blame John for the mistake．He wasn't here when we decided what to do．So_____ he about the plan．
    ? A．wasn't
    ? B．was known
    ? C．can't be known
    ? D．couldn't have known
    ??6．My ballpen is nowhere to be found，I _____ while I was playing football．
    ? A．must drop it
    ? B．should have dropped it
    ? C．must have dropped it
    ? D．had dropped
    ??7．It _____? be Li Ming who took my dictionary away．It be Zhang Hua who did it．
    ? A．can't；must
    ? B．mustn't；must
    ? C．needn't；can
    ? D．may not；can
    ??8．The streets are all wet；It _____? rained heavily last night．
    ? A．should
    ? B．should have
    ? C．must
    ? D．must have
    ??9．Tom must have learned Chinese for several years， _____?he？
    ? A．mustn't
    ? B．hasn't
    ? C．didn't
    ? D．don't
    ??10．Mr Wang must be at home now， _____?he？
    ? A．mustn't
    ? B．doesn't
    ? C．isn't
    ? D．wasn't
    ??11．She must have left for Shanghai， _____?she？
    ? A．mustn't
    ? B．hasn't
    ? C．didn't
    ? D．doesn't
    ? Key：1．A2．B3．B4．B5．D6．C7．A 8．D 9．B 10．C 11．C