if条件状语从句和宾语从句

AdverbialClauseofConditionif引导的条件状语从句&宾语从句-----------复习课Sheisdoingherhomework.Ifyouarehard-working,youwillgetgoodgrades.Shegetsgoodgrades.Ifyouplaycomputergamesonweekdays,you’llbeverytiredinclassyourparentswillbesad.youwon’tgetgoodgrades.youreyeswillbepoor1)条件状语从句通常由if或unless(=ifnot)引导，从句中常用一般时代替将来时，即if或unless后的句子谓语用一般现在时。但是，主句则通常用将来时，情态动词或祈使句。时态－－主将从现主句一般将来时，从句一般现在时1.如果主句是一般将来时，从句则用一般现在时。Ifitrains（从句），Iwillstayathome.I’llgowithyouifyoudon’twanttogoalone（从句）.2.如果主句含有must,may,can等情态动词，从句也要用一般现在时。Ifyoudrivetoofast,youmayhaveanaccident.Youmuststopifthetrafficlightisred.3.如果主句是祈使句，从句同样要用一般现在时。Don’tgoandplayfootballifyoudon’tfinishyourhomework.PleasecallmeifhecomesnextSunday.if条件状语从句结构及时态RevisionIf引导条状语从句时，从句中用一般现在时代替一般将来时。1.Ifhe______(go)tothemovies,hewon’tfinishhiswork.goes2.IfI________(become)adoctor,Icanhelpothers.become3.Ifwe_______(have)time,wewillgototheparktomorrow.have4.如果你去，我也去。Ifyougo,Iwillgo.5.如果明天下雨，请带雨衣。raincoatPleasetakearaincoatifitrains.Ifyouarefreethisweekend,whatwillyoudo?IfIamfree,…sleepwatchTVplaycomputergamespracticeIfyouwanttogetgoodmarks,dowhat?Don’tdowhat?•Ifyouwanttogetgoodmarks,__________.•Ifyouwanttogetgoodmarks,•don’t__________.studyhardlistentoteacherscarefully.dohomeworkbyyourself.copyyourhomework.talkintheclasscheatintheexamsIf条件句的替代形式：（1）祈使句+and/or+陈述句（谓语动词通常用将来时态）。其中，and表示句意顺承；or表示转折，意为“否则”。e.g.Ifyouworkhard,you’llpasstheexameasily.=Workhard,andyou’llpasstheexameasily.Ifyoudon’tworkhard,you’llfallbehindothers.=Workhard,oryou’llfallbehindothers.（2）用介词with,without的替代形式：e.g.Ifthereisnowater,thefishmaydie.=Fishmaydiewithoutwater.Ifyouhelpme,I’llfinishmytaskontime.=Withyourhelp,I’llfinishmytaskontime.If在宾语从句中翻译为“是否”If在条件状语从句中翻译为“如果”I’llgotoseeyouifIamfreenextweek.Iwanttoknowifheisateacher.whether1.if在句中的含义不同2.if在从句中的位置不同If引导的宾语从句放在主句之后；而if引导的状语从句可放在主句之前也可放在主句之后=Ifitdoesn’train,Iwillgoouttomorrow.Iwillgoouttomorrowifitdoesn’train.Idon’tknowifthetrainhasarrived.If引导的条件状语从句放于句首时多用逗号隔开；而if引导的宾语从句则不能。3.时态要求上有区别If引导条件状语从句的时态为一般现在时记住“主将从现”1.Iwanttoknowifthereasportsmeetingnextmonth.doesn’trainwillbe2.Ifitdoesn’train,we’llgooutIf引导的宾语从句的时态由主句及本身时态决定；1.Canyoutellmeifshecancometothemeeting?2.Shewillnotgothereifitisrainytomorrow.3.Ican’tguessifshewillbeangry.4.Ifwehelpeachother,wewillgetgoodresults.1IfI_______________(notunderstand）,Iwillaskmyteacherforhelp.2IfI__________(copy)yourhomework,Iwillcheatmyself.3Idon’tknowifit______(rain)tomorrow.4MyteacheraskedmeifI_________(finish)myhomeworkalready.don’tunderstandcopywillrainhadfinishedif的用法2.引导条件状语从句：译为“如果，假如”(1)if从句+祈使句(2)if从句+主句（一般将来时）(3)if从句+主句（含有情态动词）1.引导宾语从句：译为“是否”，表示不确定的概念。时态特征为：宾语从句的时态一致性（主过从过，主现从自由）Ididn’tknowifyourfathercouldcometogether.Canyoutellmeifmissyourparents?