條件狀語(yǔ)從句一、定義條件狀語(yǔ)從句是由引導(dǎo)詞if以及unless等詞引導(dǎo)的狀語(yǔ)從句。通常譯作“如果...”。表意為只有條件狀語(yǔ)從句中描述的情況發(fā)生之后，主句的動(dòng)作才能發(fā)生。一、if引導(dǎo)的條件狀語(yǔ)從句：分為真實(shí)條件句和虛擬條件句。1.真實(shí)條件句描述的情況很有可能發(fā)生。真實(shí)條件句一般遵循“主將從現(xiàn)”、主情從現(xiàn)（情指情態(tài)動(dòng)詞）、主祈從現(xiàn)（祈指祈使句）等原則。e.g.Ifitrainstomorrow,wewillstayathome.Shecanpasstheexamifsheworkshard.Pleaseletmeknowifhecomesback.2.虛擬條件句描述的情況不可能發(fā)生或發(fā)生的可能性很小。虛擬條件句的謂語(yǔ)動(dòng)詞要用虛擬語(yǔ)氣：表示與現(xiàn)在事實(shí)相反的情況從句：If+主語(yǔ)+動(dòng)詞一般過(guò)去時(shí)(Be動(dòng)詞用were)主句：主語(yǔ)+should/would/might/could+do表示與過(guò)去事實(shí)相反的情況從句：If+主語(yǔ)+had+done主句：主語(yǔ)+should/would/might/could+havedone表示與將來(lái)事實(shí)相反從句：①if+主語(yǔ)+weretodo②if+主語(yǔ)+should+do③if+動(dòng)詞過(guò)去式（be動(dòng)詞用were）主句：主語(yǔ)+should/would/might/could+doe.g.IfIwereyou,Iwouldchoosetoworkinasmalltown..Ifithadnotbeenforyourhelpyesterday,Icouldnothavecaughtthebus..Ifthingsweretobetwice，allwouldbewise.二、unless引導(dǎo)的條件狀語(yǔ)從句，意為“除非...”，相當(dāng)于“if...not”e.g.ItendtoforgetunlessIwritethemdowm.Unlessyoutakemorecare,you’llhaveanaccident.Unlessyouleavenow,youwon’tcatchthetrain.三、oncondition引導(dǎo)的條件狀語(yǔ)從句，on

condition

(that)...在……條件下，如果...e.g.Theyagreedtolendusthecaronconditionthatwereturneditbeforetheweekend.Theywillgiveusthemoneyononecondition─thatwepayitbackwithinsixmonths.四、supposing引導(dǎo)的條件狀語(yǔ)從句，意為如果，假如e.g.Supposingyouarewrong,whatwillyoudothen?Supposingthatwhitewereblack,youwouldberight.Supposingthatshedoesn'tcome,wewillstillgo.五、provided引導(dǎo)的條件狀語(yǔ)從句，意為假如，除非，以……為條件。e.g.IwillcomeprovidedIhavethetime.Providedthatyouhavethemoneyinyouraccount,youcanwithdrawupto￡100aday.六、as/solongas,incase引導(dǎo)的條件狀語(yǔ)從句，前者意為如果;只要;在……情形下；后者意為如果，萬(wàn)一。aslongas既可引導(dǎo)條件狀語(yǔ)從句，也可引導(dǎo)時(shí)間狀語(yǔ)從句；incase既可引導(dǎo)條件狀語(yǔ)從句，也可引導(dǎo)目的狀語(yǔ)從句。可根據(jù)這兩個(gè)結(jié)構(gòu)在句中的意思來(lái)判斷從句的類(lèi)型。e.g.Incasewefail，wewon'tloseheart.（引導(dǎo)條件狀語(yǔ)從句）I'llmakesomesandwichesincaseyoufeelhungryonthejourney.（引導(dǎo)目的狀語(yǔ)從句）Youcanusemyroomaslongasyoukeepitclean.（引導(dǎo)條件狀語(yǔ)從句）Youcankeepmybookaslongasyoulike.（引導(dǎo)時(shí)間狀語(yǔ)從句）七、其他表示條件的結(jié)構(gòu)：butfor若非，要不是；without沒(méi)有...的情況下e.g.Withoutyourhelp,

weshouldnothavefinishedintime.Butfortherain,weshouldhaveapleasantjourney.單項(xiàng)選擇1._____youcallmetosayyou'renotcoming,I'llseeyouatthetheatre.A.ThoughB.WhetherC.UntilD.Unless2.---Whatwouldyoudoifit___tomorrow

---Wehavetocarryiton

sincewe'vegoteverythingready.A.rainB.rainsC.willrainD.israining3.Youmustkeeponworkingintheevening____youaresureyoucanfinishthetaskintime.A.asB.ifC.whenD.unless4._______you'vetriedit

youcan'timaginehowpleasantitis.A.UnlessB.BecauseC.AlthoughD.WhenDBDA5.Intimeofseriousaccidents____weknowsomebasicthingsaboutfirstaid

wecansavelives.A.whetherB.untilC.ifD.unless6.Wewon'tkeepwinninggames____wekeepplayingwell.A.becauseB.unlessC.whenD.while7.—IhearthefamoussingerXuSongmaycometoNingbonextmonth.—Really?_______hecomes,myyoungersisterwillbeveryexcited.A.IfB.UntilC.UnlessD.Before8.—Let’sgofishingifit_____thisweekend.—Butnobodyknowsifit_______.A.isfine,willrainB.willbefine,rainsC.willbefine,willrainD.isfine;rainsCBAA9.Iwillsendyouane-mailassoonasI____inCanada.A.arriveB.arrivedC.amarrivingD.willarrive10.Ifthere________nobuyingandsellingofanimals,there______nokillinginnature.A.is;willheB.willbe;willbeC.is;isD.willbe;is11.I’mwaitingformyfriend._______,I'llgoshoppingalone.A.IfshecomesB.Ifshewon'tcomeC.Ifshedoesn'tcome12.Thestudents________haveasportsmeetingthisweekendifit________.A.won’t;rainsB.will;rainsC.won’t;willrainD.aregoingto;isgoingtorainAACA13.Ifshe________here