2017考研英語(yǔ)語(yǔ)法難點(diǎn)歸納:情態(tài)動(dòng)詞

(一)情態(tài)動(dòng)詞

一.情態(tài)動(dòng)詞的現(xiàn)在完成式的用法

情態(tài)動(dòng)詞現(xiàn)在完成式主要有兩個(gè)功能：表示已經(jīng)發(fā)生的情況和表示虛擬語(yǔ)氣。在這兩個(gè)方面must/mustn’t,;can/cann’t;need/needn’t;may/mayn’t;might/mightn’t;should/shouldn’t;

ougtht等情態(tài)動(dòng)詞+完成式表示的意思是有一定區(qū)別的

1.表示已經(jīng)發(fā)生的情況。

1)must have+過(guò)去分詞，表示對(duì)已發(fā)生情況的肯定推測(cè)，譯為“(昨天)一定……”。如：

My pain apparent the moment I walked into the room, for the first man I met asked sympathetically:” Are you feeling all right?”

[A] must be [B] had been [C] must have been [D] had to be

(答案為C)

2)can’t / couldn’t have+過(guò)去分詞，表示對(duì)已發(fā)生情況的否定推測(cè)，譯為“(昨天)一定沒(méi)……”。如：

Mary my letter; otherwise she would have replied before now.

[A] couldn’t have received [B] ought to have received

[C] has received [D] shouldn’t have received

(答案為A)

3)may / might have +過(guò)去分詞，表示對(duì)已發(fā)生的事情做不肯定、可能性很小的推測(cè)，或事實(shí)上根本沒(méi)發(fā)生，譯為“也許……”。如：

At Florida Power’s Crystal River plant, a potentially serious leakage of radioactive water may have been unknowingly caused by an electrician.

2.表示虛擬語(yǔ)氣。

1) needn’t have + 過(guò)去分詞，表示做了不必做的事，相當(dāng)于”didn’t need to do”,譯為“其實(shí)沒(méi)必要……”。如：

You needn’t have come over yourself.

As it turned out to be a small house party, we so formally.

[A] needn’t dress up [B]did not need have dressed up

[C] did not need dress up [D] needn’t have dressed up

(沒(méi)有必要穿的那么正式，體現(xiàn)是說(shuō)話者的建議，實(shí)際結(jié)果是否真的穿的很正式?jīng)]有確定，答案為D)

2)should have +過(guò)去分詞，表示應(yīng)該做某事但實(shí)際上未做，譯為“本應(yīng)該……”should not + have過(guò)去分詞表示本不應(yīng)該做某事但實(shí)際上做了，譯為“本不應(yīng)該……”。如：

I regret having left the work unfinished; I should have planned everything ahead carefully.

我本來(lái)應(yīng)該事先認(rèn)真地把每件事情規(guī)劃的很好，但實(shí)際上作者還是沒(méi)有規(guī)劃好，以至工作沒(méi)有完成。

3) ought to have +過(guò)去分詞，表示動(dòng)作按理該發(fā)生了，但實(shí)際上未發(fā)生，譯為“該……”，與should 的完成式含義類(lèi)似。如：

The porter ought to have called the fire-brigade as soon as he saw the fire in the stock, which went up in smoke .

4) could have +過(guò)去分詞，表示過(guò)去本來(lái)可以做但卻未做，譯為“完全可以……”。這點(diǎn)與ought/should/ have +過(guò)去分詞用法相似。如：

What you said is right, but you could have phrased it more tactfully.

5) may/ might have +過(guò)去分詞，表示過(guò)去可以做但實(shí)際未做，譯為“(那樣)也許會(huì)……”。如：

It might have been better to include more punchy statistics and photos of equipment in the introduction to further assist first-time office automation managers.

二.幾個(gè)情態(tài)動(dòng)詞?？嫉木湫停?/strong>