考研英語情態(tài)動(dòng)詞

時(shí)間：2023-05-07 15:42:26 考研英語我要投稿

考研英語情態(tài)動(dòng)詞

　　(一)情態(tài)動(dòng)詞

考研英語情態(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;ought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……”。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.表示虛擬語氣。

　　1) needn’t have + 過去分詞，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

　　(沒有必要穿的那么正式，體現(xiàn)是說話者的建議，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)際上作者還是沒有規(guī)劃好，以至工作沒有完成。

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

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

　　5) may/ might have +過去分詞，表示過去可以做但實(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�

　　1).may/might (just) as well “不妨，最好”，與had better相近;

　　Since the flight was cancelled, you might as well go by train.

　　既然航班已經(jīng)取消了，你不妨乘火車吧。相當(dāng)于you had better go by train。

　　2) .cannot / can’t…too …“越……越好，怎么也不過分”。注意這個(gè)句型的變體cannot…over….如：

　　You cannot be too careful when you drive a car.駕車時(shí)候，越小心越好。

　　The final chapter covers organizational change and development. This subject cannot be over emphasized .

　　3) .usedn’t 或did’t use to 為used to (do) 的否定式。

　　4).should 除了“應(yīng)該”一層意思外，考研大綱還規(guī)定要掌握其“竟然”的意思。如：I didn’t expect that he should have behaved like that. 我無法想象他竟然這樣做。

　　三.情態(tài)動(dòng)詞被動(dòng)關(guān)系的主動(dòng)表達(dá)法

　　1. want, require, worth(形容詞)后面接doing也可以表示被動(dòng)意義。

　　Your hair wants cutting