may和might的用法辨析

may和might可以表示可能性和許可。might的語(yǔ)氣比may較婉轉(zhuǎn)。此外，may也可以接動(dòng)詞的完成形式，表示可能、說(shuō)不定已經(jīng)做某事。

【例如】

I thought it might be difficult for me to learn advanced mathematics. （可能性）

May I come in, sir? （許可）

She may have gone to the hospital.

Research findings show we spend about two hours dreaming every night, no matter what we ____during the day. (cet-4 1999,1)

A) must have done

B) should have done

C) would have done

D) may have done

情態(tài)動(dòng)詞后面加動(dòng)詞完成式，有不同意義。

must have done表示一定做過(guò)某事；

should have done表示本應(yīng)該做某事，含有批評(píng)的意思；

would have done主要用于虛擬語(yǔ)氣，表示對(duì)過(guò)去的虛擬；

may have done表示可能已經(jīng)作過(guò)某事。

根據(jù)句意：研究結(jié)果表明，我們每晚有兩個(gè)小時(shí)做夢(mèng)，不管白天可能做了什么，情態(tài)動(dòng)詞后表示可能性，故答案應(yīng)為D。