unit3When和while引导的时间状语从句.ppt

unit3When和和while引引导的的时间状状语从句从句过去进展时的概念及构成过去进展时的概念及构成构成：主语+was/were+doing sth+时间状语概念：表示过去某一时刻或某段时间正在进展的动作指示词：then、at that time、once等连用，或者用另一动作来表示过去的时间。when和和while的用法与区别的用法与区别1、延续性动词与非延续性动词延续性动词指动作可以延续一段时间，而不是瞬间完毕。如：work study drink eat 等非延续性动词指动作极为短暂，瞬间完毕。如：start begin hit jump knock等When与while引导的时间状语从句When表示当时候。从句中既可以用延续性动词，又可以用非延续性动词，这些动词既可以表示动作，又可以表示状态。从句中的动作既可和主句动作同时发生，又可在主句动作之前或之后发生。如：Mary was having dinner when I saw her.The boy was still sleeping when his mother got home yesterday evening.When与与while引导的时间状语从句引导的时间状语从句lWhile表示“在时候、“在期间。它强调主句的动作与从句的动作同时发生，或主句的动作发生在从句的动作过程中。While从句必须是表示动作或状态的延续性动词。如：lThe weather was fine while we were in Beijing.lShe called while I was out.l假如主句的动作在从句的动作过程中发生，从句常用进展时，如：lWhile we were swimming someone stole our clotheslDont talk so lould while others are working.Summary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。总是指一个时间段，从句中必须用延续性动词。3.统一时态：主句过去式，从句也是过去式。Exercises:fill with“while or“when1.May was talking on the phone,her sister walked in2.Rita bought her new dog,it was wearing a little coat.3.I saw Carlos,he was singing louldly.4.I was dancing,he was singing louldly.5.Linda finally saw David,he was jumping with a dog.6.I was cleaning my room the fire broke out,WhileWhileWhenWhenWhenWhenExercises7.I was walking in the street the accident happened.8.you have a meeting,you should turn off your mobile phone.9.you have PE class,you should wear sports shoes.10.I was doing my homework,the phone rang.11.it was raining,the plane took off.12.the teacher was speaking to class,he stood up suddenly.whenWhenWhenWhileWhileWhile