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第1页共3页Ifyougototheparty,you’llhaveagreattime!语法讲解和习题巩固（附答案)条件状语从句条件状语从句表示主句动作发生的条件，在初中阶段常由if(如果)和unless引导，表示假如有从句的动作发生就会有主句的动作发生。例如：Pleasecallmeifheisathome.假如他在家的话，请给我打电话。：一、if条件句if条件句：条件句用于陈述语气，表示假设的情况可能发生，其中if是“如果”的意思。构成条件从句主句时态If＋一般现在时主语＋shall/will+动词原形例句Ifhecomes,hewilltakeustothezoo.用法：(一)条件状语从句通常由连词if引导，意为“如果、假如”，主句不能用begoingto表示将来，而应该用shall，will。Ifyouleavenow,youarenevergoingtorememberit.(错误)Ifyouleavenow,youwillneverrememberit.(正确)if“如果”，引导条件状语从句，主句用一般将来时，从句则用一般现在时，如：Ifitrainstomorrow,Iwon'tclimbthehills.另外，主句是祈使句或含有情态动词，从句也用一般现在时。如：PleasecallmeifhecomesnextSunday.Canyoucallthepolicemanifyouareinthetrouble.注意宾语从句中的if与条件状语从句if的区别。宾语从句中的if的意思是“是否”，相当于whether，引导宾语从句，时态需根据语境确定。如果主句用一般现在时，从句可以根据具体情况选用任何时态，通常情况下，如果主句用一般过去时，从句必须用过去式的某种形式。例如：Idon'tknowifitwillraintomorrow.我不知道明天是否会下雨。Ourteachersaidtherewasgoingtobeafootballmatchthenextmonth.我们说下月将有场足球比赛。(二)unless引导的条件句，表示强烈的否定。翻译为“除非……”。“非……不可。”Iwon’tgounlessheasksme.他不来请我我就不去。Youwillfailunlessyouworkharder.你不努力就会失败的。Don’tcomeunlessIcallyou.我不叫你就别来。（注意）unless从句里的谓语只能是肯定式，因为本身unless表示否定。误:Unlessyoudonotwork,youwillfail.正：Unlessyouworkhard,youwillfail.正：Ifyoudon’tworkhard,youwillfail.注意：在学习条件状语从句时，同学们要注意以下几点：（1）、时态如果主句是一般将来时态，这时从句不可以用将来时态，而要用一般现在时。例如：Iwon’tgotherewithyouifitrainstomorrow.如果明天下雨的话，我就不和你一起去那儿了。（2）、主从句的位置大多数情况下，从句可以位于主句之前，也可以位于主句之后。不过从句在前时，主从句之间必须用逗号隔开。例如：Pleasetellmeifhecomesback.=Ifhecomesback,pleasetellme.如果他回来了，请告诉我一声。（3）、if的两面性if引导条件状语从句时意为“如果”，如果引导宾语从句则意为“是否”。请比较：1)Wewillgooutifitisfinetomorrow.2)Idon’tknowifthetrainhasarrived.第2页共3页句1)中if引导的是状语从句。这个从句表示“条件”，整个句子的意思是“如果明天天气好，我们就出去”。句2)中if引导的是宾语从句，充当谓语动词don’tknow的宾语，整个句子的意思是“我不知道火车是否到了”。I'llwritetoyourparentsifyou'relateagain.如果你再迟到,我就给你父母写信。(之后）Unlessyouhavealreadyspokentoher,Iwillbeveryangry.除非你已经对她说过了,否则我会很生气。（之前）（3)在条件状语从句中的从句和主句如果主语相同，有时它可以替代从句和主句，它就是“祈使句+and/or+简单句”。其中and表示句意顺承；or则表示转折，意为“否则”。例如：Ifyouworkharder,you’llpasstheexam.=Workharder,andyou’llpasstheexam.如果你再努力些，你就会通过考试。Ifyoudon’thurryup,you’llmissthetrain.=Hurryup,oryou’llmissthetrain.如果你不快点儿，你就赶不上火车了。Ⅰ.单项选择1.Ifyou_____totheparty,you’llhaveagreattime.A.willgoB.wentC.goD.going2.Itwillbealongtime____Peter_____hiswork.A.since,hasfinishedB.after,finishesC.when,willfinishD.before,finishes.3.Idon'tknowifhe_____tomorrow．Ifhe_____，I'lltellyou．A．willcome；comesB．comes；comesC．comes；willD．iscoming；iscoming4.Weifangisfamous______kites.A.forB.toC.onD.with5.I____hertheanswerifshe____me.A.cantell,willaskB.willtell,willaskC.wouldtell,askD.willtell,asks6.–Whatareyougoingtodotomorrow?--We’llgotothelibrarytomorrowifit____.A.isn’trainB.rainC.won’trainD.doesn’train7.—Doyouknowwhenhewillcomebacktomorrow?--Sorry,Idon’tknow.Whenhe____back,I’lltellyou.A.comesB.willcomeC.comeD.maycome8.Whatwillyoudoifyou_____totheoldfolk’shomevisit?A.goB.wentC.goingD.willgo9.IfIeat____food,I’llbeveryfat.A.toomanyB.manytooC.toomuchD.muchtoo10.I’llgivethebooktohimifhe___herenextSunday.A.willcomeB.comesC.iscomingD.came11.There____anEnglishfilminourschooltomorrow.A.isgoingtohaveB.willhaveC.isgoingtobeD.has12.Couldyoutelluswhere____？A.willthenextOlympicGamesheldB.thenextOlympicGameswillbeheldC.wouldthenextOlympicGamesbeheldD.thenextOlympicGameswouldbeheld13.Whenmymotherreturnedlastnight,I____abook.A.readB.amreadingC.wasreadingD.amgoingtoread14.What____you____whenitbegantorain?A.do,doB.were,doingC.are,doingD.did,do15.I’llwakeyouupwhenhe____back.第3页共3页A.willB.isgoingtocomeC.comesD.come16.Ifit______sunnytomorrow,I____boating.A.isgoB.willbe,goC.is,willgoD.willbe,willgo17.----whatwillyoudoifit______tomorrow,----I’llstayathomeandwatchTV.A.rainB.rainsC.willrainD.israining18.I’llgotomeetyou，ifI_____freethen.A.wouldbeB.willbeC.amD.was19.Workhardifyou_____togetgoodgrades.A.wantedB.wantingC.wantD.willwant20.Iwanttoknowifyou_____tothepartytomorrow.---IwillifIfree.A.willcome;amB.come;amC.willcome;willbeD.come;willbeII.同义句转换1.Runfast,oryou’llbelateforschool._____you_____________fast,you’llbelateforschool.2.Youcanbuythedictionaryifyoutakeenoughmoneywithyou.Takeenoughmoneywithyou,_________________buythedictionary.3.Ifthereisnoair,noneofuscanlive.Noneofuscanlive___________.4.Workharder,oryouwillfailintheexam.youworkharder,youwillfailintheexam.5.Unlessyoutakemorecare,you’llhaveanaccident.youtakemorecare,you’llhaveanaccident.Ⅲ.用所给词的适当形式填空1.Ifshe______(finish)workearly,she______(go)home.2.Iftheweather______（be）fine，we_______(go)forawalk.3.IfI_____(have)timetonight,I_______(finish)thebookI’mreading.4.IfIt______(rain)nextweekend,we_______(notbeableto)plantthevegetable.5.Ifit_______(rain),we______(stay)athome.6.Ifshe______(arrive),she_____(phone)me.7.Ifhe_____(call),tellhimI’llringback.8.Unlessyou_____(work)harder,you_____(not)passthetheexams.9.He_____(notspeak)toyouunlessyou_____(speak)tohimfirst.10.Idon’tknowifit______(rain)tomorrow.Ifit_____(rain),we_____(notgo)toschool.1---5CDAAD6---10DAACB11---15CBCBC16--20CBCCAII.同义句转换1.Runfast,oryou’llbelateforschool.Ifyoudon'trunfast,you’llbelateforschool.2.Youcanbuythedictionaryifyoutakeenoughmoneywithyou.Takeenoughmoneywithyou,andyoucanbuythedictionary.