when和while引导的时间状语从句与这一时态连用.doc

when和while引导的时间状语从句与这一时态连用。所以区别when和while的用法成了这一单元的难点。 （一）、when，while都有“当……时候”的意思。 when既可表示某一点时间，也可以表示某一段时间 。在when引导的时间状语从句中，其谓语动词可以是延续性的，也可以是非延续性的，可与主句中的谓语动词同时发生，也可在其后发生。 例如： 1、I was just reading a book when she came into my room. 她走进我房间时，我正在看书。 2、Were you writing when the teacher came in? 老师进来的时候，你在写信吗？ 3、When he was a child he was always trying out new ideas. 他小时候就常常试验一些新的设想。 （二）、while只能表示某一段时间，不能表示某一点时间。在while引导的时间状语从句中，其谓语动词只能是延续性的，而且也只能与主句中的谓语动词同时发生或存在。 例如： 1、While Jim was mending his bike, Lin Tao came to see him. 正当吉姆修自行车时，林涛来看他。 2、You can’t do your homework while you’re watching TV. 你不能一边看电视一边做家庭作业。 （三）、另外，when和while的区别还在于：while引导的时间状语从句多用进行时态，而when引导的时间状语从句多用一般时态。 例如： 1、While they were talking , the bell rang. 正在他们谈话的时候，上课铃响了。 2、I was doing my homework when my mother came back home yesterday evening. 昨天晚上妈妈回家的时候，我正在做家庭作 1. ----------she comes , I shall tell her to wait for you.A. When ? ? B. As ? C. While ? ? D. What2. ----------she got older, she got wiser.A. When ? ? B. As ? C. While ? ? D. That3.----------Peter was reading , his wife was cooking.A. When ? ? B. As ? C. While ? ? D. That when ? as while ① when 表示较短的时间,有的时候也可以指一段时间。如:When he was young, he could do eat much more than his brother. ② while常表示一段较长的时间,强调主句谓语动词与从句谓语动词同时发生。如:你的第三道题就是这样。③ 只用as, 不用when或while的时候。A) 用于表示同一个人的两种动作交替进行,指一边……,一边……。如:The girl dances as she sings on the stage. B)表示两个同步发展的动作或行为,译为随着……。如:As time went on, she became more and more worried. when和while的区别 都表示“当......时候”的区别。请观察以下句子： While in Vienna he studied music.他在维也纳时学习音乐。While he was eating, I asked him to lend me $2.当他正在吃饭时,我请他借给我二英镑。While two detectives were keeping guard at the door, two? others? opened the parcel.这时两个侦探把着门,另外两个打开包裹。While I read, she sang.我看书时，她在唱歌。I met her while I was at school.当我在学校的时候我遇见了她。 Edison was not a good student when he was a young boy.爱迪生小时候不是一个成绩好的学生。When the plane arrived, some of the detectives were waiting inside the main building while