外研八年级下册：过去进行时when as和while的区别课件.ppt

1、While和和when1)when可指时间点可指时间点,又可指时间段又可指时间段,从句中从句中可用可用延续性动词延续性动词,也可用也可用非延续性动词。非延续性动词。2)while总是指一个时间段总是指一个时间段,从句中从句中必须用延必须用延续性动词续性动词。1.以以when和和while引导的时间状语从句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和非延续性动词延续性动词延续性动词指动作可以延续一段时间指动作可以延续一段时间,而不是而不是瞬间结束。瞬间结束。如如:work、study、drink、eat等。等。非延续性动词非延续性动词指动作极为短暂，瞬间结束。指动作极为短暂，瞬间结

2、束。如如:start、begin、hit、jump、knock等。等。when和while的区别 whilewhile指一段时间，指一段时间，whenwhen引导的时间状引导的时间状语从句中的动词可以是终止性动词，语从句中的动词可以是终止性动词，也可以是延续性动词，而也可以是延续性动词，而whilewhile从句中从句中的动词必须是延续性动词。的动词必须是延续性动词。whenwhen 说明从句的动作和主句的动作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；可以是同时，也可以是先后发生；whilewhile 则强调主句的动作在从句动作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

3、动作同的发生的过程中或主从句两个动作同时发生。时发生。画表格画表格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)He was singing when I was reading.2)Father is cooking when Tom is sleeping.3)Please say hello to Mike when you see him.when两边的时态也可以不等1)Kate was swimming when her parents came back.2)They were trying to run away when t

4、he policeman broke into the house.3)The light went off when they were talking.while连接的句子，后面必须用进行时（现在/过去进行时）1)A car hit her while she was thinking about a question.2)The books fell off from the shelf while they were listening to the radio.3)While we are playing football,a noise comes from downstairs.

5、While+过去进行时，句子（一般过去时）过去进行时，句子（一般过去时）句子（一般过去时）句子（一般过去时）While+过去进行时，过去进行时，小结：用小结：用while和和when填空，填空，看看它们后面的句子的时态。看看它们后面的句子的时态。如果是如果是过去过去时，必须用时，必须用when.如果是如果是进行进行时，必须用时，必须用while（没有（没有while选项的时候用选项的时候用when)过去进行时过去进行时一般过去时一般过去时When/whilewhen小结：在作“当时候”时，when可以替换while.1)Mary was happy while/when she was doi

6、ng her homework.2)When/while they are watering flowers,a stranger shout at them.后面都是ingWhile 还有“然而”的意思。此时不能用when 代替。1）While Tom is speaking,I am listening2)I am listening while Tom is speaking.WeareintheofficewhiletheyareintheclassroomWhile:两个状态（延续），介词短语两个状态（延续），介词短语.Heisstrongwhilehisbrotherisweak.

7、1._Jenniferwasreadingamagazine,hissisterwaslisteningtothepopmusic.A.WhileB.When C.Whattime2.Iwastryingtodrawacatontheboard_theteachercamein.A.whileB.whenC.whattime3.MybestfriendvisitedmyhousewhileI_dinnerinthekitchen.A.cookedB.cookingC.wascooking练一练练一练ABC6.DickgavemeanotewhileI_inthelibrary.Iguesshe

8、madeittosay“sorry”toyou.(2007黄冈市黄冈市)A.amreadingB.wasreadingC.readsD.willread B 用while 和when填空1）He was copying a text _ his brother came in.2)Mary learnt a lot _ she was only 7.3)_ I was drinking,father came in.4)They bought many food _ Mike was studying.5)_ the thief was stealing the DVD,a lot of people came in.6)_ he fell down,he came up with an idea.whenwhenWhile/whenwhile/whenWhile/whenWhen