1. 情態動詞+have+done:
一、 “must+have+done”表示對過去事情的肯定推測,譯成“一定做過某事”,該結構只用於肯定句.
1.It must have rained last night,for the ground is wet.昨晚一定下雨了,因爲地面還是溼的.
2.You must have been mad to speak to the servant.你和僕人說話,一定是發瘋了.
二、 “can't+have+done”表示對過去事情的否定推測,譯成“不可能做過某事”.
1.Mr.Smith can't have gone to Beijing,for I saw him in the library just now.史密斯先生不可能去北京了,我剛纔還在圖書館見過他.
2.Mary can't have stolen your money.She has gone home.瑪麗不可能偷你的錢,她回家去了.
三、 “can+have+done”表示對過去行爲的懷疑,用於疑問句,譯成“可能做過……嗎?”.
1.There is no light in the room.Can they have gone out?屋裏沒有燈,他們可能出去了嗎?
2.There is nowhere to find them.Where can they have gone?到處找不到他們,他們可能到什麼地方去呢?
四、 “could+have+done”是虛擬語氣,表示對過去事情的假設,意思是本來能夠做某事而沒有做.
He could have passed the exam,but he was too careless.本來他能夠通過考試,但是他太粗心.
五、 “may+have+done”表示對發生過的事情的推測,意思是“可能已經”或“也許已經”,用於肯定句中.
—What has happened to George?
—I don't know.He may have got lost.
—喬治發生了什麼事?
——我不知道,他可能迷路了.
六、 “might+have+done”表示對過去事情的推測,might與may意思相同,但可能性更小.多用於虛擬語氣結構中.
1.He might have given you more help,even though he was busy.(MET90) 他或許會多給你一些幫助,即使他很忙.
2.She might have achieved greater progress,if you had given her more chances.如果你多給她點機會,她可能已經取得更大的成績.
七、 “would+have+done”虛擬語氣,表示對過去事情的假設,意思是“本來會做”.
1.I would have told you all about the boy's story,but you didn't ask me.我本來會告訴你這個小男孩的故事,但是你沒有問我.
2.Without your help,I wouldn't have achieved so much.沒有你的幫助,我是不會取得如此大的成績.
八、 “should+have+done”意思是“本來應該做某事,而實際沒做.” “shouldn't+have+done”表示本來不應該做某事,而實際做了.含有指責對方或自責的含意.
1.Tom,you are too lazy.The work should have been finished yesterday.湯姆,你太懶惰了,這項工作本來應該昨天就做完的.
2.Look,Tom is crying.I shouldn't have been so harsh on him.看,湯姆哭了,我本來不應該對他如此嚴厲.
九、 “ought to+have+done”表示過去應該做而實際並沒有做,譯成“理應做……”,往往表示遺憾.與“should+have+done”用法基本一樣.
I ought to have gone home last Sunday.我理應上星期日回家.
You ought not to have given him more help.你不應該幫助他那麼多.
十、 “need+have+done”表示本來需要做某事而沒有做.“needn't+have+done”則表示“本來不需要做某事而做了”.
I needn't have bought so much wine—only five people came.我本來沒有必要買這麼多酒,只來了五個人.
He need have hurried to the station.In that case,be wouldn't have missed the train.他本來需要快點去車站,那樣的話,他就不會誤了火車.