when-while用法

when和while的用法和区别while和when都是表示同时，到底句子中是用when还是while主要看从句和主句中所使用的动词是短暂性动作（瞬时动词）还是持续性动作。1、若主句表示的是一个短暂性的动作，而从句表示的是一个持续性动作时，两者都可用。如：Hefellasleepwhen[while]hewasreading.他看书时睡着了。Imethimwhen[while]Iwastakingawalkinthepark.我在公园散步时遇到了他。2、若主、从句表示两个同时进行的持续性动作，且强调主句表示的动作延续到从句所指的整个时间，通常要用while。如：Don’ttalkwhileyou’reeating.吃饭时不要说话。Ikeptsilentwhilehewaswriting.在他写的时候，我默不作声。3、若从句是一个短暂性动作，而主句是一个持续性动作，可以when但不用while。如：Whenhecamein,Iwaslisteningtotheradio.他进来时，我在听收音机。Itwasraininghardwhenwearrived.我们到达时正下着大雨。4、若主、从句表示的是两个同时(或几乎同时)发生的短暂性动作，一般要用when。如：Ithoughtofitjustwhenyouopenedyourmouth.就在你要说的时候，我也想到了。如果是进行时态，一般是持续性的。如果是过去式，一般是短暂性动作。对于，填写when还是while的问题，通常首先看主句和从句中的时态，再根据以上4个规律来判断填写那个单词。主句从句短暂性when/while持续性（过去时）（过进：was/were+doing）Hefellasleepwhen[while]hewasreading.持续性while持续性（一般现在/过去时）（过进：was/were+doing）Don’ttalkwhileyou’reeating.Ikeptsilentwhilehewaswriting.（现进：am/is/are+doing）（现进：am/is/are+doing）（过进：was/were+doing）（过进：was/were+doing）IwaswatchingTVwhileMymotherwascooking(动作同时发生)持续性when短暂性（过进：was/were+doing）（过去时）IwaslisteningtotheradioWhenhecamein.短暂性when短暂性（过去时）（过去时）Ithoughtofitjustwhenyouopenedyourmouth.用when或while填空1________Tomwaseatingsupper,itbegantorainoutside.2Don'tuseyourphone________youaredrivingacar.3Whatwereyoudoing______Mr.Zhoucamein?4Jimisgoodatmath_____MaryisgoodatEnglish.5WewerewatchingTV___theelectricitywasoff..6________Peterwassleeping;athiefbrokeintohishouse.7Itsnowed________wearrivedinTokyo.8Sheleftherhometown________shewasfive.9Iwasstudyinginthelibrary_____theUFOlanded选用when或while填空。1.Mywalletdroppedontheground____Iwaswalking.2.________Iwasfallingasleeptherewasaloudknockonthedoor.3.________hewasreading,thetelephonerang.4.Werethestudentslisteningtotheteachercarefully________theteacherwasgivingalesson?5.________thetelephonerang,Iwasdoingmyhomework.6.Wassheplayinggames________thebellwasringing?7.Thedaysgetlonger________springcomes.8.Lucywaslisteningtotheradio________LilywaswatchingTV.9.________wewerebattingonthelake,wesawafishjumpoutofthewater.10.TheyhavetheirPElessonindoors________itrains.用when,while填空：1.Iwaslisteningtotheradio_______hecamein.2._______theteachercamein,weweretalking.3._____hecameback,Iwasdoingsomewashing.4.Iwascookingdinner_______theycamehome.5.Hefellasleep____________hewasreading.6.Heaskedmeaquestion_______Iwasspeaking.7.Jimhurthisarm_______hewasplayingtennis.8.___________shewaswaitingforthetrain,shebecameveryimpatient.9.HewaswatchingTV________shewascooking.