may/might have done 推測(cè)過(guò)去

“may/might+動(dòng)詞的完成式”表示對(duì)過(guò)去發(fā)生的行為的推測(cè)。例如：

-Whatever has happened to George?
-喬治發(fā)生了什么事?
-I don't know. He may have got lost.
-我不知道，他可能迷路了。

You might have read about it in the papers.
你可能在報(bào)上已經(jīng)看過(guò)這個(gè)消息了。

（之前我們做過(guò)can have done用法小結(jié)，can have done表推測(cè)時(shí)都是對(duì)過(guò)去進(jìn)行推測(cè)，但是may have done不僅可以推測(cè)過(guò)去）

may/might have done 推測(cè)現(xiàn)在

“may/might+動(dòng)詞的完成式”表示對(duì)現(xiàn)在情況的推測(cè)。例如：

She might have got up now.
現(xiàn)在她可能已經(jīng)起床了。

may/might have done 預(yù)測(cè)未來(lái)

“may/might+動(dòng)詞的完成式”表示推測(cè)將來(lái)某時(shí)之前的情況。例如：

He may have left when you get there.
等你到達(dá)的時(shí)候他可能已經(jīng)離開(kāi)了。

注意：may have done 和 might have done 表推測(cè)時(shí)，might 所表示的可能性比 may 小，語(yǔ)氣較委婉：

How quickly time passed! It might have happened yesterday.
時(shí)間過(guò)得好快啊！這事好像就發(fā)生在昨天。

He might have seen the surprise in my face.
他或許已經(jīng)看到了我驚異的表情。

might have done 表輕微責(zé)備

might have done 除了能夠表推測(cè)，還能表示過(guò)去本來(lái)可以做而實(shí)際并沒(méi)有做。這時(shí)帶有輕微的責(zé)備之意。例如：

The proposal might have been refused.
這個(gè)建議本該拒絕的。（有輕微的責(zé)備之意）

I might have taken another path.
我本可以走另一條路。

may not/mightn't have done 表“可能不”

之前我們講到過(guò) can't/couldn't have done 是表示“不可能”，而 may not/mightn't have done 則是表示“可能不”，要注意區(qū)分哦：

He can't have been at the meeting, he's on a business trip this week.
他不可能有出席會(huì)議，他這周出公差。

We couldn't have done it without you.
沒(méi)有你我們肯定完成不了。

They may not have known it beforehand.
他們事先可能不知道這事兒。

They mightn't have regarded me as their friend.
他們可能沒(méi)有把我當(dāng)作朋友看待。