第九講　情態動詞和虛擬語氣一、情態動詞考點透析 (could)，be able to。 只有現在式can和過去式could兩種形式可用于現在式、過去式、將來時、完成時。要表示“能夠做某事”可用can或be able to但若要說過去的確運用了某種能力做成了某件事情就只能用was/were able to表將來具備的能力只能用will/shall be able to。(1)If you study hard，you will be able to express freely in English in three months.

　　如果你努力學習三個月后你就能自由地用英語表達了。(2)The fire spread through the hotel very quickly but everyone was able to get out.

　　大火迅速在酒店蔓延但每個人最終還是逃出去了。是can的過去式但是在很多情況下特別是在口語中它表示語氣的委could提問時不能用could回答而要用can或may。would用于疑問句時也表委婉語氣回答時應該用will。(1)－Could I borrow your dictionary?能借用一下你的詞典嗎？－Yesurse you can.

　　——可以當然可以。(2)－Could I call you by the first name?我可以直呼你的名字嗎？－Yes行可以的。(3)－Would you be so kind as to explain the word?請你好心地解釋一下這個字好嗎？－Yes好的哪個字？都可表示可能但may/might 不能用于問句用于否定句、疑問句、感嘆句表示驚異、懷疑一般不用于肯定句。如果用于肯定句則表示偶爾發生某事的可能或某人某物一時的特點。(1)－Are you coming to Jeff's party?I'm not sure.I might go to the concert instead.

　　——說不好我可能會去音樂會。(2)－Where can Mr.Li be?李先生會在哪里呢？－Sorrycan go to ask Mr.Zhang.He may help you.

　　——對不起我不知道。你可以去問問張先生他可能會幫到你。(3)Mr.Bush is on time for everything.How can it be that he was late for the opening ceremony?

　　布什先生做什么都準時開幕式時他怎么就遲到了呢？(4)We enjoy good weather in January，but sometimes it can be terribly cold.

　　我們這兒一月份天氣都很好但是偶爾也會很冷的。表推測用于肯定句其否定式要用can't。對現在表示推測：；can't do對正must be doing；can't be doing對過去表示推測：；can't/couldn't have done(1)－There were already five people in the car車里已經有五人了但他們還是設法帶上了我。－It couldn't have been a comfortable journey.2)Jack can't have arrived yet，otherwise he would have telephoned me.

　　杰克不可能已經到了否則他會給我電話的。(3)Put on more clothes，you must be feeling cold with only a shirt on.

　　多穿點衣服只穿一件襯衣你一定覺得冷吧。(4)I didn't hear the phone.I must have been asleep.

　　我沒有聽5．情態動詞完成式的意義。過去可能做過過去本來可以做某事但沒有做過去一定做過可能已經做過本來可以做但沒做 have done過去可能做過過去本來可以做但沒做過去不可能做過某事(not) have done

　　過去本該(不該)做但卻沒做ought (not) to have done

　　過去本該(不該)做但卻沒做(做了)過去本來沒必要做但卻做了(not) have done寧愿過去做了(沒做)注意：must have done都表推測。其區別在于可能性的大小。must have done表很有可能表有可能表可能性很小則為“不可能”。(1)I told Sally how to get here，but perhaps I should have written it out for her.

　　我告訴過莎莉怎么來這兒不過也許我該寫給她的。(2)Sorry，I'm late.I might have turned off the alarm clock and gone back to sleep again.

　　對不起我遲到了。我可3)I was really anxious about you.You shouldn't have left home without a word.

　　我真為你擔心你不該什么也不說就離家出走的。(4)Tom needn't have got up that early since it was Sunday and he had nothing important to do.

　　湯姆本來沒有必要起那么早的因為是星期天他也沒什么重要事情。(5)I would rather not have blamed him because he was a child after all.

　　我寧愿沒有責備他。因為他畢竟只是個孩子。關于should的主要用法。(1)It's already seven o'clock.Jack should be here at any moment.

　　已經七點鐘了杰克隨時都可能來的。(should表推測意為“隨時都會來”真該來了”)(2)－When can I come for the photos? I need them tomorrow afternoon.我什么時候來拿照片？我明天下午要用。－They should be ready by 12：00.(should：應該)十二點前應該就可以了。(3)You can't imagine that a well-behaved gentleman should be so rude to a lady.

　　你難以想象一個舉止優雅的紳士對女士居然這么粗魯。(should表驚異意為“居然”、“竟然”)(4)If he should fail to come，ask Mr.Zhang to attend the ceremony instead.

　　要是他萬一來不成就叫張先生代替出席這個典禮吧。(should表語氣較強的假設意為“萬一”)(5)We should have studied last night，but we went to the concert instead.(should have studied：我們本該學習的但卻沒有學習)我們昨晚本該學習的但是我們卻去了音樂會。關于shall的用法。用于第一人稱、第三人稱疑問句中表示說話人征求對方意見或向對方請示。用于第二、第三人稱表示說話人給對方的命令、警告、允諾或威脅。(1)Shall I go on reading the text?

　　我要繼續讀課文嗎？(shall：征求意見)(2)You shall be punished one day for what you've done.

　　總有一天你會因你的所作所為受到懲罰的。(shall：威脅警告)3)He shall get what he deserves.I promise it.

　　他會得到他應該得到的我保證。(shall：允諾)

　　按照句子結構的語法性和句子連貫的要求在空白處填上適當的情態動詞或根據提示使用正確形式的情態動詞。________ (not) use a clock to wake me up because at six o'clock each morning the train comes by my house.

　　2．I________ (not) thank you too much for all your help to my son while we were away from home.

　　3．—________ you interrupt now? Can't you see I'm on the phone?

　　—Sorry Sir, but it's urgent.

　　4．I got close enough to hear them speaking Chinese, and I said “Ni Hao” just as I ________do in China.

　　5．We ________ (not) have bought so much food now that Suzie won't be with us for dinner.

　　6．One of our rules is that every student________wear school uniform while at school.

　　7．I'm going to Europe on vacation together with John if I ________ find the money.

　　8．—You have to believe in yourself.No one else will, if you don't.

　　—I ________ (not) agree more.Confidence is really important.

　　9．The new law states that people ______(not) drive after drinking alcohol.

　　10．It's quite warm here; we ________(not) turn the heating on yet.

　　11．—No one ________ be compared with Yao Ming in playing basketball.

　　—Oh, you are really his big fan.

　　12．The police still haven't found the lost child, but they're doing all they ________．________ (not) be the postman at the door.It's only six o'clock.

　　14．—How's your new babysitter?

　　—We ________ (not) ask for a better one.All our kids love her so much.

　　15．—I don't really like James.Why did you invite him?

　　—Don't worry.He ________ not come.He said he wasn't certain what his plans were.

　　16．If you

　　________ smoke, please go outside.

　　17．If you ______ go, at least wait until the storm is over.

　　18．—Shall I inform him of the change of the schedule right now?

　　—I am afraid you ________， in case he comes late for the meeting.

　　19．I ________ (not) worry about my weekend.I always have my plans ready before it comes.

　　20．—Will you read me a story, Mummy?

　　—OK.You________ have one if you go to bed as soon as possible.

　　答案：　2.can't　3.Must　4.might　5.needn't　7.can　8.couldn't/can't　9.mustn't　10.needn't　11.can　12.can　13.can't　14.couldn't　15.might　16.must　17.must　18.must　19.needn't　20.shall二、虛擬語氣考點透析虛擬語氣在非真實條件句中的用法。

　　時間 if從句動詞 主句動詞

　　與現在事實相反 did(be改為were) should/would/could/might＋do與過去事實相反 had＋done

　　should/would/could/＋have done

　　與將來事實可能相反 did/should do/were to do should/would/could/might do如：(1)If she were here，everything would be all right.(But she isn't here now.)

　　如果她在這兒一切就好辦了。

　　(2)If you had come five minutes earlier，you would have met the famous pop singer.

　　如果你早來五分鐘你就可以看見那個著名的流行歌手了。(3)If it were to rain tomorrow，the outing would be canceled.

　　要是明天下雨的話郊游就要取消了。(4)If you should visit our school tomorrow，you would see how beautiful it is.

　　如果你明天來參觀我們學校的話你就會發現它有多美！

　　＋賓語從句 (賓語從句

　　時間 動詞形式 例句

　　與現在事實相反的愿望 did(be改為were) I wish I were ten years younger.我希望年輕十歲。

　　與過去事實相反的愿望 had＋過去分詞 He wishes he had gone to the concert last night.他希望

　　將來難以實現的愿望 should/would/＋動詞原形 The last chance has been lost.How he wishes he could have another chance.最后的機會已經失去了他多么希望能再有一次機會。3.在非真實條件狀語從句中如果含有were可將if省去將were放在主語前構成倒裝。如：(1)What would have happened had Bob walked farther，as far as the river bank?

　　要是鮑勃走得更遠些一直走到河堤上的話會發生什么呢？(2)Should I fail this time，I would wait for another chance.

　　萬一我這次失敗了我會等待下次機會的。在非真實條件狀語從句中有時條件從句與主句動作發生的時間是不一致的這時動詞的形式要根據動詞所表示的時間(1)If you had worked harder，you wouldn't be afraid of the examination now.

　　如果你早點努力的話現在你就不會害怕考試了。(2)If he had followed the doctor's advice，he would be quite all right now.

　　如果他早聽了醫生的話他現在就好了。有時假設的情況并不or，otherwise，with，without，but for(要不是)等詞經常出現在含蓄虛擬條件句中。如：(1)He hesitated for a moment before kicking the ball，otherwise he would have scored a goal.

　　在起腳射門時他猶豫了一下否則他就進球了。(2)Without electricity human life would be quite different today.

　　如果沒有電人類今天的生活就會完全不同。(3)Under more favorable conditions，the rice would grow much better.

　　如果條件更有利的話水稻會長得更好。(4)But for your help，I would still be working in the lab now.

　　要不是有你幫忙我現在還在實驗室埋頭苦干呢。情態動詞的完7．在下列句型中動詞要用虛擬語氣： if it were not for要不是因為……要不是因為……要是……就好了！(表強烈愿望)(1)If only he were here!

　　要是他在這就好了！(2)If it had not been for the snow，we could have climbed the mountain yesterday.

　　要不3)If only he had lain quietly as the doctor instructed，he would not suffer so much now.

　　要是他能像醫生囑咐的那樣安靜地躺著的話現在他就不會受這么多罪了。后的從句中動詞要用虛擬語氣。如表示與現在的情形相反動詞用過去式；如表示與過去的情形相反動詞用had＋過去分詞。如：(1)Tom is com ing soon，but I would rather he came tomorrow.

　　湯姆很快就到了可我寧愿他明天再來。(2)Jane is crying sadly.I would rather you hadn't told her the bad news.

　　珍妮在傷心流淚呢我寧愿你沒有把那壞消息告訴她。

　　Ⅰ.用所給動詞的適當形式填空。________(book)a table earlier，we wouldn't be standing here in a queue.

　　2.If he had spent more time practicing speaking English before，he________(be) able to speak it much better now.

　　3．－It rained cats and dogs this morning.I'm glad we took an umbrella.－Yeah________(not take) one.

　　4．Eye doctors recommend that a child's first eye exam________(be) at the age of six months old.

　　5．I should not have laughed if I________(think)you were serious.

　　6．Sorry, I am too busy now.If I ______ (have) time, I would certainly go for an outing with you.

　　7．We lost our way in that small village, otherwise we ________(visit) more places of interest yesterday.

　　8．If my car __________(be) more reliable, I would have driven to Lhasa instead of flying last summer.

　　9．Had they known what was coming next, they________ (have) second thoughts.

　　10．Jack is a great talker.It's high time that he ________(do) something instead of just talking.

　　11．We ________(face) the difficulty together, but why didn't you tell me?

　　12．Don't handle the vase as if it ________(be) made of steel.

　　13．We would have called a taxi yesterday if Harold ____________(not offer) us a ride home.

　　14．I____________(go) through that bitter period without your generous help.

　　15．—Where are the children? The dinner's going to be completely ruined.

　　—I wish they ________ (be not) always late.

　　16．If it________(be not) for your help，I could not have entered this famous university.

　　17．I would rather I________(not grow) up so that I would not worry about such a thing.

　　18．It is high time that we________(take)action to protect wildlife.

　　19．My mom suggests that we________(eat)out for a change this weekend.

　　20．If we________(take)the other road，we might have arrived here in time this morning for the meeting.

　　Ⅱ.用所給動詞的適當形式填空。Tom and Peter are twins. They look as if they 1.______ (be) the same person. Both the two boys are smart, but Tom is hard-working while Peter is lazy. Tom always wins the first place in the exams while Peter doesn't.However, people believe if Peter 2.______ (work) as hard as Tom，he would do as well as his brother in his study.

　　At home, their parents suggests that they 3.______(finish) their homework before playing computer games. But Peter insists that it 4.______ (be) OK to play games first as long as he can hand in his homework in time. Their mother gives in in the end.

　　One day, when doing his homework, Tom found he made a serious mistake. So he put his exercise book aside and used another one. When Peter found the previous exercise book, he struck out Tom's name and signed his name on its cover happily, and handed it in as his own homework the next day.

　　When the teacher told the truth to the twins' mother, she was very angry and shouted at Peter, “How I wish you 5.______ (be) as diligent as your brother! Now it's time that I 6.____ (give) you a good lesson. And you 7.______ play any computer games for a month！” Mom. Without a computer for such a long time, I 8.______ (die). I would rather you 9.______ (ask) me to do the dishes for a month alone.”Peter was upset.

　　“If you 10.________ (finish) your homework on time yesterday, you wouldn't be punished now，”said the mother.

　　答案：　2.would be　3.hadn't taken(should)be　5.had thought　6.had　7.would have visited　8.had been　9.might have had　10.did　12.were　13.hadn't offered　15.were not　16.were not　18.took　19.(should) eat　2.worked　3.(should) finish　4.is　6.gave/should give　7.mustn't　8.would die　10.had finished