by-the-time用法

1、By the time用法详解? by the time 意为“到时候（为止）“，是一个介词短语，在句中经常起连词作用，引导时间状语从句。它的主要用法如下：?1.如果从句中的谓语动词是一般过去时，那么主句中的谓语动词通常用过去完成山，表示“截止到从句动作发生时，主句动作已经完成，即过去的过去”。例如：By the time he returned home , the rain had stopped.? By the time I got to the station, the train had already gone。? 2.如果从句中的谓语动词为一般现在时/或现在完成时（表示将来）,

2、那么主句中的谓语动词常为将来完成时，表示“截止到将来某一时间为止，主句动作将已经完成”。By the time you get back , I shall have finished the work.?By the time I graduate next year, I will have lived here for 5 years.?By the time of next term , we will have learned 3000 words.? 3.如果主句动作不强调已经完成，只是说明某个时候的状况，（主句是be的系表形式或者是表示像 know, find, believe等

3、表示认知的持续性动词，则往往用一般时态，不用完成时态。）此时主句不用完成时，而应根据实际需要选用适当的时态，此时 by the time 相当于when。 例如：? He was out of breath by the time he reached the top.By the time the bus came, so many people were waiting that it was a free fight to get on it.公共汽车来的时候，等车的人很多，成了一场挤车的混战。? By the time he went abroad, he was fourteen.出

4、国那年他 14 岁。? By the time the war was over , death and suffering were to be seen everywhere.? 在战争结束的时候，到处可见死亡和饥饿。这里没有“死亡和饥饿”已经完成的意思，只是描述当时这个时间点的状况。所以用过去时。? 巩固练习：?1.（2005 天津卷） By the time Jane gets home , her aunt for London toattend a meeting.A. will leave B. leaves? C. will have left D. left? 2. By t

5、he time you have finished this book, your meal cold.（2012四川卷）? A. gets B. has got C. will get D. is getting?3.（2009 d匕京卷） When I talked with my grandma on the phone , she soundedweak, but by the time we up , her voice had been full of life.A. were hanging B. had hung? C. hungD. would hang? 4. Did yo

6、u see Xiao Li at the party ?No, by the time I arrived.A. she ' d left B. she ' s left? C. she was left D. she must leave5. By the time I saw the angry expression on his face, I what I had toface.A. knew B. have known? C. would know D. had known6. （2008 四川卷）The telephone , but by the time I g

7、ot_ indoors , it stopped.A. had rung B. was ringing C. rings D. has rung?7. （2008 山东卷） By the time he realizes he into a trap, it ' ll betoo late for him to do anything about it.A. walks B. walked C. has walked D. had walked情态动词用法总结如下表情态 动词用法否定式疑问式简答式can1 .表示能力（体力，技能）2 .允许或许可（口语中常用）3 .可能性（表猜测，用于

8、否定旬或疑问旬中）4 .用于肯定句表示理论可能性can not / cannot /can ' t doCan- do - ?Yes, - can.No,can' t.couldcouldn ' t domay可以（问句中表示请求） 可能，或许（表推测） 祝愿（用于倒装句中）may not doMay- do - ?Yes, - may.No,mustn' t/can ' t.mightmight not doMight do？Yes, - might No, -might not.must必须，应该（表主观要求） 肯定，想必（肯定句中表推测）must

9、not/mustn ' t doMust do ？Yes, - must.No,needn' t/don ' t havehave to只好，不得不（客观的必须， 有时会和人称的变化）don' t have to doDo have to do？Yes,do.No,don' t.ought to应当（表示义务责任，口语中多用 should ）oughtnotto/oughtn ' t to doOught - to do ？Yes, - ought.No,oughtn' t.shall用三人称征求对方意见用于一二人称表小许诏、 叩令、警告

10、、威胁等shall not/shan ' tdoShall do？Yes, - shall.No,shan' t.should应当，应该（表义务责任） 本该（含有责备意味）should not/shouldn 't doShould do - ?will意愿，决心请求，建议，用在问句中would 比较委婉willnot/won ' t doWill/Would do - ?Yes, - will.No,won' t.wouldwould not/wouldn ' t dodare敢（常用于否定句和疑问句中）dare not/daren '

11、 t doDare do ？Yes, - dare.No,daren' t.need需要，必须（常卅十台定句和 疑问句中）need not/needn ' t doNeed 7。？Yes, - must.No,needn' t.used to过去常常（现在已不再）usednot/usedn ' t/ usen' t to do didn ' t use toUsed- to do ？Did - use to do？Yes, - used.No,use(d)n ' t.Yes,did.No, - didn ' t.do学法提炼mus

12、t have done表示主观上对过去已经发生的行为进行推测，意为“想必，准是，一定做了某事”;may/might have done表示对过去已发生行为的推测，意为“很有可能”；can-have donecannot have done1） could have done用于对过去可能性的推断，息为 可能，在肯定句中，指 某事可能是事实或可能会发生”；用于疑问句或否定句，表示对过去情况的怀疑、否定 或惊讶；2） could have done 忌为 本来可以；差点就要，指 某事可能发生但实际上未发 生”常用于虚拟语气，表示惋惜、遗憾等；might have done表示“本来可能，但实际上没

13、有发生的事情”。另外，还可以表示“本来应该或 可以做某事”之意，含有轻微的责备语气。should/ought to have done1）用于肯定句时,表示本该做某事，而实际上未做；附于否定句时，则表示不该做的 事反而做了 ；2）用于对过去的推断，说话人认为“按理应当、理应如此"，说话人不能肯定，只是 试探性地得出结论，语气婉转；3）对已发生的事表不“惊奇、失望、愤怒”等情绪。needn' t have done表不做了本来小必去做的事。注思：didn t need to do表示 没必要做而实际上也没有做某事”will/would have done用于推测过去，意为“想必

14、、可以肯定”，指“说话人确信某事已发生，但并不确知”，并用于二、三人称：1）如果以现在为时间点，可以用"will have done "2）如果以过去为时间点，只能用“would have done "3） will have done也用于推测将来某个时间前已经元成。D.If they to do this work, he might do it some other way.A. wereB. shouldC. will can2. I was told yesterday that the company meto Romenext week for a

15、businessconference.A. should have sentB. were going to sendC. should be sendingD. should send3. Let ' s take a walk,?A. will weB. don't weC. do weD.shall we4. He was a good swimmer so heA. couldB. mightswim to the river bank whenC. shouldthe boat sank.D. wasable toA. Can, must, mayD. Must, c

16、an, may7."We didn't s“HeA. mustn't attend5. I went to the doctor's yesterday, I had to wait for half an hour before he see me.A. canB. mayC. mightD.could6. -this book be yours?- No, it not be mine. Itbe his.B. May, might, mustC. Can, may, mustee him at the lecture yesterday.-X”it.B.

17、 can't have attendedC. would have not attendedD. needed have attendedC. can have lostB. must have snowedD. must have been snowingC. aren't youC. mustn't youC. can8. They the plane, or perhaps they have been prevented from coming forsome reason.A. can have missedB. may have missedD. may h

18、ave lost9. Since the ground is white, it last night.A. had snowedC. must be snowing10. You must be fifty,?A. mustn't youB. needn't youD. mayn't you11. You must have seen him off yesterday,?A. haven't youB. didn't youD. needn't you12. - That must be a mistake.-No .it be.A. can

19、'tB. isn't able toD. was able to13. He had known the matter before you told him, so you have told it to him.A. mustn'tB. can'tD. shouldn't14. How so?A. dare you to sayB. dare you sayD. dare to say15. You are their teacher. You care of them.A. should to takeB. might to takeD. need

20、 to takeC. needn'tC. do you dare sayC. ought to take16. She is studying medical science now but she a lawyer.A. used to beB. would beC. wereYoureturn the book now. You can keep it till next week if you like.A. can'tB. mustn'tC. needn'tD. maynot2. I wish I to the moon one day.A. can f

21、lyB. an able to flyC. could flyD. wasable to fly3. If my lawyer here last Saturday, he _ me from going.A. had been; would have preventedB. had been; would preventC. were; would preventD. were; would have prevented4. If it for the snow, we the mountain yesterday.A. were not; could have climbedB. were

22、 not; could climbC. had not been; could have climbedD. had not been; could climb5. Without electricity human lifequite difficult today.A. isB. will beC. would have beenD.would be6. Jenny have kept her word. I wonder why she changed her mind.A. mustB. shouldC. needD.would 7. We last night, but we went to the concer