bythetime用法

1、Bythetime用法详解?bythetime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匣，表示戳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：?Bythetimehereturnedhome,therainhadstopped.?BythetimeIgottothestation,thetrainhadalreadygone。?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）,那么主句中的谓语动词常为将来完成时，表示戳止到将来某一时间为止

2、，主句动作将已经完成”。?Bythetimeyougetback,Ishallhavefinishedthework.?BythetimeIgraduatenextyear,Iwillhavelivedherefor5years.?Bythetimeofnextterm,wewillhavelearned3000words.?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bythetime相当于when。

3、例如：?Hewasoutofbreathbythetimehereachedthetop.?Bythetimethebuscame.somanypeoplewerewaitingthatitwasafreefighttogetonit.公共汽车来的时候，等车的人很多，成了一场挤车的混战。?Bythetimehewentabroad,hewasfourteen.出国那年他14岁。?Bythetimethewarwasover,deathandsufferingweretobeseeneverywhere.?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

4、时间点的状况。所以用过去时。?巩固练习：?1.（2005天津卷）BythetimeJanegetshome,herauntforLondontoattendameeting.?A.willleaveB.leaves2.Bythetimeyouhavefinishedthisbook,yourmealcold.（2012四川卷）A.getsB.hasgotC.willgetD.isgetting3.（2009d匕京卷）WhenItalkedwithmygrandmaonthephone,shesoundedweak,butbythetimeweup,hervoicehadbeenfullofli

5、fe.A.werehangingB.hadhungC.hungD.wouldhang4.IDidyouseeXiaoLiatthepartyNo,bythetimeIarrived.A.shedleftB.shesleftC.shewasleftD.shemustleave5.BythetimeIsawtheangryexpressiononhisface,IwhatIhadtoface.A.knewB.haveknownC.wouldknowD.hadknown6.（2008四川卷）Thetelephone,butbythetimeIgotindoors,itstopped.A.hadrun

6、gB.wasringingC.ringsD.hasrung7.（2008山东卷）Bythetimeherealizesheintoatrap,itllbfeoolateforhimtodoanythingaboutit.A.walksB.walkedC.haswalkedD.hadwalked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，附十否定旬或疑问句中）4 .用于肯定句表示理论可能性cannot/cannot/cantdoCandoYes,can.No,cant.couldcouldntdomay可以（

7、问句中表示请求）可能，或许（表推测）maynotdoMaydoYes,may.No,mustnt/canC.willhaveleftD.leftmight祝愿（用于倒装句中）mightnotdoMightdoYes,mightNo,mightnot.must必须，应该（表主观要求）肯定，想必（肯定句中表推测）mustnot/mustntdMustdooYes,must.No,neednt/donhavehaveto只好，不得不（客观的必须，有时会和人称的变化）donthavetodoDohavetodoYes,do.No,dont.oughtto应当（表示义务责任，口语中多用should）ou

8、ghtnotto/oughtntbdoOught-todoYes,ought.No,oughtnt.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、威胁等shallnot/shandotShalldoYes,shall.No,shant.should应当，应该（表义务责任）本该（含有责备意味）shouldnot/shouldndoShoulddo-will意愿，决心请求，建议，用在问句中would比较委婉willnot/wondotWill/WoulddoYes,willNo,wont.wouldwouldnot/wouldntdodare敢（常用于否定句和疑问句中）daren

9、ot/darentdDaredooYes,dare.No,darent.need需要，必须（常卅十台定句和疑问句中）neednot/needntdNeeddooYes,must.No,neednt.usedto过去常常（现在已不再）usedUsed-todoYes,used.tnot/usednt/u：nttododidnusetodoseDidusetodoNo,use(d)nt.Yes,did.No,didnt.学法提炼musthavedone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/mighthavedone表示对过去已发生行为的推测，意为很有可能”

10、；canhavedonecannothavedone1）couldhavedone用于对过去可能性的推断， 意为何能， 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）couldhavedone意为不来可以；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；mighthavedone表示本来可能；但实际上没有发生的事情”。另外，还可以表7K本来应该或可以做某事”之意，含有轻微的责备语气。should/oughttohavedone1）用于肯定句时,表示本该做某事，而实际上未做；用于否定句时，则表示不该做的事反而做了

11、；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。neednthavedone表不做I本来小必去做的事。注思：didntneedtodofcr没必要做而实际上也没后做某事”will/wouldhavedone用于推测过去，意为想必、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willhavedone;2）如果以过去为时间点，只能用“wouldhavedone;3）willhavedone也用于推测将来某个时1可前已经元成。Iftheytodot

12、hiswork,hemightdoitsomeotherway.A.wereB.shouldC.willD.can2. IwastoldyesterdaythatthecompanymetoRomenextweekforabusinessconference.A.shouldhavesentB.weregoingtosendC.shouldbesendingD.shouldsend3. Letstakeawalk,A.willweB.dontweC.doweD.shallwe4. Hewasagoodswimmersoheswimtotheriverbankwhentheboatsank.A.

13、couldB.mightC.shouldD.wasableto5.Iwenttothedoctorsyesterday,Ihadtowaitforhalfanhourbeforeheseeme.A.canB.mayC.mightD.could6. -thisbookbeyours-No,itnotbemine.Itbehis.A.Can,must,mayB.May,might,mustcan,may7. -Wedidntseehimatthelectureyesterday.一Heit.”A.mustntattendC.wouldhavenotattended8. Theytheplane,o

14、rperhapstheyreason.C.Can,may,mustD.Must,B.canthaveattendedD.neededhaveattendedhavebeenpreventedfromcomingforsomeA.canhavemissedB.mayhavemissedC.canhavelostD.mayhavelost9. Sincethegroundiswhite,itlastnight.B.musthavesnowedC.mustbesnowingD.musthavebeensnowing10.Youmustbefifty,A.mustntyouB.needntyouC.a

15、rentyouD.mayntyou11.Youmusthaveseenhimoffyesterday,A.haventyouB.didntyouC.mustntyouD.needntyou12.-Thatmustbeamistake.-No.itbe.A.cantB.isntabletoC.canD.wasableto13.Hehadknownthematterbeforeyoutoldhim,soyouhavetoldittohim.A.mustntB.cantC.needntD.shouldnt14.HowsoA.dareyoutosayB.dareyousayC.doyoudaresay

16、D.daretosay15.Youaretheirteacher.Youcareofthem.A.shouldtotakeB.mighttotakeC.oughttotakeD.needtotake16.Sheisstudyingmedicalsciencenowbutshealawyer.A.hadsnowedA. usedtobeB. wouldbeC.wereY)ureturnthebooknow.Youcankeepittillnextweekifyoulike.A.cantB.mustntC.needntD.maynot2.IwishItothemoononeday.A.canfly

17、B.anabletoflyC.couldflyD.wasabletofly3.IfmylawyerherelastSaturday,hemefromgoing.A.hadbeen;wouldhavepreventedB.hadbeen;wouldpreventC.were;wouldpreventD.were;wouldhaveprevented4.Ifitforthesnow,wethemountainyesterday.A.werenot;couldhaveclimbedB.werenot;couldclimbC.hadnotbeen;couldhaveclimbedD.hadnotbee

18、n;couldclimb5.Withoutelectricityhumanlifequitedifficulttoday.A.isB.willbeC.wouldhavebeenD.wouldbe6.Jennyhavekeptherword.Iwonderwhyshechangedhermind.A.mustB.shouldC.needD.would7.Welastnight,butwewenttotheconcertinstead.A.musthavestudiedB.mightstudyC.shouldhavestudiedD.wouldstudy8.CouldIborrowyourdictionary?Yes,ofcourseyou.A.mightB.willC.canD.should9.Ifhe,hethatfood.-Luckilyhewassenttothehospitalimmediately.A.waswarned;wouldnottakeB.hadbeenwarned;wouldnothavetakenC.wouldbewarned;hadnottakenD.wouldhavebeenwarned;hadnottaken10.Itold