初中英语-外研八年级下册：过去进行时when-as和while的区别(共14张ppt)

While和when1)when可指时间点,又可指时间段,从句中可用延续性动词,也可用非延续性动词。2)while总是指一个时间段,从句中必须用延续性动词。1.以when和while引导的时间状语从句1)延续性动词和非延续性动词延续性动词指动作可以延续一段时间,而不是瞬间结束。如:work、study、drink、eat等。非延续性动词指动作极为短暂，瞬间结束。如:start、begin、hit、jump、knock等。when和while的区别•while指一段时间，when引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而while从句中的动词必须是延续性动词。•②when说明从句的动作和主句的动作可以是同时，也可以是先后发生；while则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。画表格when和while具体的区别1.When的用法比较活，用在状语从句中，两边的时态可以相等.1)HewassingingwhenIwasreading.2)FatheriscookingwhenTomissleeping.3)PleasesayhellotoMikewhenyouseehim.when两边的时态也可以不等1)Katewasswimmingwhenherparentscameback.2)Theyweretryingtorunawaywhenthepolicemanbrokeintothehouse.3)Thelightwentoffwhentheyweretalking.while连接的句子，后面必须用进行时（现在/过去进行时）1)Acarhitherwhileshewasthinkingaboutaquestion.2)Thebooksfellofffromtheshelfwhiletheywerelisteningtotheradio.3)Whileweareplayingfootball,anoisecomesfromdownstairs.While+过去进行时，句子（一般过去时）句子（一般过去时）While+过去进行时，小结：用while和when填空，看看它们后面的句子的时态。如果是过去时，必须用when.如果是进行时，必须用while（没有while选项的时候用when)过去进行时一般过去时When/whilewhen小结：在作“当…时候”时，when可以替换while.1)Marywashappywhile/whenshewasdoingherhomework.2)When/whiletheyarewateringflowers,astrangershoutatthem.后面都是ingWhile还有“然而”的意思。此时不能用when代替。1）WhileTomisspeaking,Iamlistening2)IamlisteningwhileTomisspeaking.WeareintheofficewhiletheyareintheclassroomWhile:两个状态（延续），介词短语.Heisstrongwhilehisbrotherisweak.1._______Jenniferwasreadingamagazine,hissisterwaslisteningtothepopmusic.A.WhileB.WhenC.Whattime2.Iwastryingtodrawacatontheboard_________theteachercamein.A.whileB.whenC.whattime3.MybestfriendvisitedmyhousewhileI_______dinnerinthekitchen.A.cookedB.cookingC.wascooking练一练ABC6.—DickgavemeanotewhileI______inthelibrary.—Iguesshemadeittosay“sorry”toyou.(2007黄冈市)A.amreadingB.wasreadingC.readsD.willreadB用while和when填空1）Hewascopyingatext_______hisbrothercamein.2)Marylearntalot______shewasonly7.3)__________Iwasdrinking,fathercamein.4)Theyboughtmanyfood__________Mikewasstudying.5)__________thethiefwasstealingtheDVD,alotofpeoplecamein.6)______hefelldown,hecameupwithanidea.whenwhenWhile/whenwhile/whenWhile/whenWhen