【文章內(nèi)容簡介】
推測。例如: Your mother must have been looking for you. 你媽媽一定一直在找你?!?)推測的否定形式,疑問形式用can39。t, couldn39。t表示。例如:Mike can39。t have found his car, for he came to work by bus this morning. 邁克一定還沒有找回他的車,因為早上他是坐公共汽車來上班的。 注意:could, might表示推測時不表示時態(tài),其推測的程度不如can, may。 情態(tài)動詞+ have +過去分詞 1) may(might) have + done sth, can (could) have + done sth 表示過去,推測過去時間里可能發(fā)生的事情。例如: Philip may (might) have been hurt seriously in the car accident. 菲力浦可能在車禍中受了重傷?! hilip can (could) have been hurt seriously in the car accident.2) must have +done sth,對過去時間里可能發(fā)生的事情的推測,語氣較強,具有肯定,諒必的意思。例如: Linda has gone to work, but her bicycle is still here. 琳達已經(jīng)去上班了,但她的單車還在這兒?!? She must have gone by 。3) ought to have done sth, should have done sth表示本應(yīng)該做某事,而事實上并沒有做。否定句表示不該做某事而做了。例如: You ought to (should) have been more careful in this experiment. 你當(dāng)時在做試驗時應(yīng)該更仔細點?! e ought not to have thrown the old clothes 。(事實上已扔了。) ought to 在語氣上比should 要強。4) needn39。t have done sth表示本沒必要做某事,但做了。例如:I dressed very warmly for the trip, but I needn39。t have done so. The weather was hot. 旅行時,我衣服穿得較多,其實沒有必要。那時天很熱。5) would like to have done sth表示本打算做某事,但沒做。例如: I would like to have read the article, but I was very busy then. 我想讀這篇文章,但太忙了一直沒讀。 should 和ought to 除了上述的用法,兩者還可表示想必一定,按理應(yīng)該的意思。例如:I ought to be able to live on my salary. 靠我的薪水,想必也能維持了。It ought to be ready now. 想必現(xiàn)在準備好了吧。They should be there by now, I think. 現(xiàn)在他們該到那兒了。The po