情态动词表示猜测时语气从强到弱的顺序是:must,will,would,can,may,could,might.
〔5〕用于表目的或让步状语从句中。
She was studying English so that she might 英语，以便能阅读英代书籍。失败者英文
He died in order that others might live. 他为了别人而牺牲了。
1. 表示请求、建议等，would更委婉。 Will / Would you pass me the ball, plea?
2. 表示意志、愿望和决心。 I will never do that again. They asked him if he would go abroad.
3.表示过去反复发生的动作或某种倾向。would表示过去习惯时比ud to正式，且没有“现已无此习惯”的含义。
During the vacation, he would visit me every other day.
4.表示估计和猜想。 It would be about ten o’clock when she left home.
二、may、might表示允许
(1) 表示请求允许(即请求别人允许自己做某事)，两者都可用，只是 might 表示的语气较委婉(不表示过去)：may的否认形式为may not，但表示“不可以”、“阻止”等意思时常用must not(musn't)代替may not
May /Might I come round in the morning? 我早上来可以吗？
I asked her if I might /may call and e her. 我问她我可否来看她。
(2) 表示给予允许(即自己允许别人做某事)，通常要用 may而不用might：
You may leave whenever you plea. 你高兴随时可以走。
You may go or stay, according as you decide. 是去是留由你自己决定。
A：May /Might]I stay? 我可以留下吗? (表请求，用两者)B：Yes, you may. 可以。(表允许，不能用 might)
【注】在通常情况下，may 表示允许时，总是针对“现在”或“将来”而言，假设要表示已经给予或已经存在的允许，则通常不用 may，而用can：
Nowadays, children can do what they like. 现在小孩子喜欢干什么就可以干什么。
It’s unfair. He can stay and I have to leave. 这不公平，他可以留下，而我却得离开。
三、表示推测〔两者都可用，只是 might 比 may 语气更不确定，表示的可能性更小〕construction
(1) 两者均可用于肯定句和否认句，但用于疑问句时，may通常不用于句首〔在很正式的文体中，may 可用于否认疑问句的句首〕，但可用于疑问句的句中(如特殊疑问句等)，而might尽管可以用于疑问句的句首，通常会改用其他句式(如用could等)：May we not be making a big mistake? 我们难道不可能在犯大错误吗？
He may [might] know the answer. 他可能知道答案。
And who may [might] she be? 那么她会哪一位呢？ Might it be true? 那会是真的吗？
(2) ① 后接动词原形，表示对现在或将来的推测：
椭圆公式You may [might] be right. 你可能是对的。 He may [might] tell his wife. 他也许会告诉他妻子。
② 后接动词进行式，表示动作正在进行或将要发生：I may [might] be going back in the fall. 我可能秋天回去。 She may [might] be waiting for us. 她可能在等我们。
③ 后接动词完成式，表示对过去可能发生的事进行推测： They may have en him. 他们可能见到过他。
I might have come to a wrong conclusion. 我或许得出了错误的结论。四大名著翻译
might 后接动词的完成式，除表示对过去的推测外，还有以下用法(不用may)：
1) 过去某事可能发生并没发生：A lot of men died who might have been saved．很多人本来可以获救的却死了。2) 表示委婉的批评或责备：You might have made greater progress. 你的进步本来可更大一些的。
You might at least have answered my letter. 你至少可以回我一封信嘛。
(3)may和can表推测时的区别： can和may均可表示推测，can用于否认句和疑问句，may用于肯定句和否认式。两者均可用于否认句，但是含义不同：cannot=不可能，may not=可能不。比较：
It can't be true. 这不可能是真的。 It may not be true. 这可能不是真的。
表示热烈的祝贺(4)加强推测的语气：假设要加强推测的语气，表示较大的可能性，可在may, might后加副词well：
You may well be right. 你很可能是对的。
That may well have been their intention．这很可能是他们的意图。
(5)用于 may /might(just) 为“不妨”“还是…为好”等，用 might 比用 may 语气更委婉：
I'm ready, so I might as well go now．我已准备好，因此不妨现在就走。大学学制
There's nothing to do, so I may /might as well go to bed. 既然没什么事可做，我还是去睡觉为好。
【注】might as well 还可用于指过去的情况或用于比较两个令人不愉快的情况：
This holiday isn't much fun, we might as well be back home. 这个假日过得真没意思，我们还不如呆在家里。
(6)郁郁寡欢什么意思may 用于表示祝愿 主要用于正式场合或书面语中：
May you be happy! 祝你幸福! May God bless you! 愿上帝保佑你!
1. C.can D.will
3.It ____last night,for the ground was wet this morning.A.must have rained B.may have rained C.must rain D.might rain
4.Mary ______ be in Paris,for I saw her in the town only a few minutes ago.A.mustn't B.can't C.shouldn't D.may not
5—There were already five people in the car but they managed to take me as well.—It ____a comfortable journey.
A.can't be B.shouldn't be C.mustn't have been D.couldn't have been
6.Hurry up,our teacher ____for us at the school gate.A.must be waiting B.must wait 粽子 英文C.might waiting D.can be waiting
7.She doesn't answer the doorbell,she _____ be asleep. A.might to C.must have D.should
8."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
9.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
8.The streets are all wet;It _____ rained heavily last night. B.should havedocument D.must have
9.Tom must have learned Chine for veral years, _____ he? A.mustn't wiperB.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
