新東方白易禮：英語四級(jí)考試語法筆記(四)

　　I don’t see how I could have done otherwise. 我看不出我當(dāng)時(shí)還有別的做法。

　　Who could have supposed you were going to do such a thing? 誰會(huì)想到你會(huì)做出這樣的事情。

　　Nobody could have foreseen such a calamity. 這樣的災(zāi)禍誰也不會(huì)預(yù)想到。

　　(2)could have done(但不是can)在肯定句中，表示“那時(shí)本來可以…;差點(diǎn)就要…”，有時(shí)用來進(jìn)行婉轉(zhuǎn)地批評(píng)(與might同意，但語氣更強(qiáng)一些)：

　　We could have solved the problem in a more reasonable fashion. 這個(gè)問題我們本來是可以更合理得解決的。

　　He could have told her, but he did not choose to. 他本來可以告訴她的，但他不愿這樣做。

　　When she heard the news, she could have cried. 聽了這消息，她簡(jiǎn)直要哭出來了。

　　I could have died laughing. 我簡(jiǎn)直要笑死了。

　　You could have been more considerate. 你其實(shí)可以想的更周到一些。

　　We could have started a little earlier. 我們其實(shí)可以更早一些動(dòng)身的。

　　The result could have been better. 結(jié)果本可以更好一些。

　　5、should/ought to have done的含義。 “should/ought to have+過去分詞”表示“過去應(yīng)該做謀事卻沒有做”;“should not/ought not to have+過去分詞”表示“做了不應(yīng)該做的事”。含有責(zé)備或遺憾的意思。例如：

　　You shouldn’t /oughtn’t to have come here alone at such a late hour. 你這么晚的時(shí)候本不一該一個(gè)人來這里的。(實(shí)際是一個(gè)人來的)

　　She should/ought to have gone there alone. 她本該一個(gè)人去那里的。(實(shí)際上不是)

　　You should have come here ten minutes earlier. 你本應(yīng)該早10分鐘來才是。

　　The boy shouldn’t have been playing the piano. 那孩子不應(yīng)該一直在彈鋼琴。

　　6、might, may, must表示推測(cè)時(shí)的區(qū)別: may，might, must可表示 推 測(cè)“可能”.根據(jù)表示可能性的大小，我們把這三個(gè)詞排列為：might

　　It might rain tomorrow. (將來)明天可能下雨。

　　They might be watching TV now. (現(xiàn)在)他們可能正在看電視。

　　Jane might have visited the Summer Palace last year. (過去)去年珍妮可能去過頤和園。

　　He may have something important to do. (現(xiàn)在)他可能有更重要的事要做。

　　They may have been to Shanghai last summer. (過去)去年夏天他們可能去過上海。

　　There must be something wrong with him. (現(xiàn)在)他肯定出問題了。

　　He must have made a mistake. (過去)他一定是犯了個(gè)錯(cuò)誤。

　　第四部分 幾個(gè)用法的區(qū)別

　　1、 can 和be able to的區(qū)別。can在表示“能力”時(shí)與be able to同義。但是can的時(shí)態(tài)形式不如be able to多。在一般將來時(shí)和現(xiàn)在完成時(shí)中只能用be able to。如：

　　She will be able to dance in a week. 她再過一星期就會(huì)跳舞了。

　　Nobody has ever been able to do it. 從來沒有人能夠做這事。

　　在過去時(shí)中，could表示具備某種能力，但不一定做事;而was able to表示努力設(shè)法去做謀事，成功后說明有能力，相當(dāng)managed to do或succeeded in doing。這時(shí)，could和was able to是不能互換的。例如：

　　When he was a boy, he could swim across the river in fifteen minutes. 他小時(shí)侯，15分鐘就能游過那河。(could表示能力，但不一定這么做)

　　He was able to swim across the river in fifteen minutes last week.

　　=He managed to swim across the river in fifteen minutes last week.

　　=He succeeded in swimming across the river in fifteen minutes last week.

　　上周他15分鐘就游過了那河。(was able to表示真這樣做了，而且成功了。這里不能用could)