來源:本站原創(chuàng)    點擊率:    發(fā)布: 2013-1-22

武漢新東方英語學習，情態(tài)動詞的現(xiàn)在完成式的用法

 酷學酷玩冬令營英語學習    情態(tài)動詞現(xiàn)在完成式主要有兩個功能：表示已經(jīng)發(fā)生的情況和表示虛擬語氣。在這兩個方面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，表示對已發(fā)生情況的肯定推測，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，表示對已發(fā)生情況的否定推測，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，表示對已發(fā)生的事情做不肯定、可能性很小的推測，或事實上根本沒發(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，相當于”didn’t need to do”,譯為“其實沒必要……”。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，實際結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，表示應該做某事但實際上未做，譯為“本應該……”should not + have過去分詞表示本不應該做某事但實際上做了，譯為“本不應該……”。如：
i regret having left the work unfinished; i should have planned everything ahead carefully.
我本來應該事先認真地把每件事情規(guī)劃的很好，但實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，表示動作按理該發(fā)生了，但實際上未發(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際未做，譯為“（那樣）也許會……”。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.