if条件状语从句和宾语从句.ppt

Revision AdverbialClauseofConditionif引导的条件状语从句 宾语从句 复习课 Sheisdoingherhomework Ifyouarehard working youwillgetgoodgrades Shegetsgoodgrades Ifyouplaycomputergamesonweekdays you llbeverytiredinclass yourparentswillbesad youwon tgetgoodgrades youreyeswillbepoor 1 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 Revision If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 goes 2 IfI become adoctor Icanhelpothers become 3 Ifwe have time wewillgototheparktomorrow have 4 如果你去 我也去 Ifyougo Iwillgo 5 如果明天下雨 请带雨衣 raincoat Pleasetakearaincoatifitrains excellent Ifyouarefreethisweekend whatwillyoudo IfIamfree sleepwatchTVplaycomputergames practice Ifyouwanttogetgoodmarks dowhat Don tdowhat Ifyouwanttogetgoodmarks Ifyouwanttogetgoodmarks don t studyhardlistentoteacherscarefully dohomeworkbyyourself copyyourhomework talkintheclasscheatintheexams If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 verygood 2 用介词with without的替代形式 e g Ifthereisnowater thefishmaydie Fishmaydiewithoutwater Ifyouhelpme I llfinishmytaskontime Withyourhelp I llfinishmytaskontime if引导的条件状语从句和if引导的宾语从句的区分 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 whether 1 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 train willbe 2 Ifitdoesn train we llgoout If引导的宾语从句的时态由主句及本身时态决定 找出下列句子中哪些是if条件状语从句 哪些是if宾语从句 1 Canyoutellmeifshecancometothemeeting 2 Shewillnotgothereifitisrainytomorrow 3 Ican tguessifshewillbeangry 4 Ifwehelpeachother wewillgetgoodresults If引导的条件状语从句或宾语从句的练习 1IfI notunderstand Iwillaskmyteacherforhelp IfI copy yourhomework Iwillcheatmyself Idon tknowifit rain tomorrow MyteacheraskedmeifI finish myhomeworkalready don tunderstand copy willrain hadfinished summary if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