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 cant do your homework while youre 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. Thatwhen as while 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. 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。 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 others were waiting on the airfield.当飞机抵达时,一部分侦探等在主楼里面,而另一部分则等在停机坪上。When I came home my wife was cooking dinner.我回家时，妻子在做晚饭。通过观察，我们可以这样理解：when引导的从句里动作发生的时间相对主句动作发生的时间要短些；while引导的从句里的动作发生的时间相对主句而言更长些。333 as，when，while意为although（尽管），but（但是），seeing that（鉴于）A 只有在形容词+as+主语+to beto seemto appear这一结构中，as才意为thoughalthough（尽管）： Tired as he was he offered to carry her相当于：Though he was tired he offered to carry her 尽管他很累了，他还主动提出要背着她。 Strong as he was，he couldnt lift it 尽管他力气很大，他仍提不起这个东西。B while可意为but，用于表示强调对比：At seameanson a ship，whileat the seameansat the seaside “At sea”意为“在船上”，而“at the sea”意为“在海滩上”。 Some people waste food while others havent enough 一些人糟踏食物而另一些人却食不果腹。while可以意为although，这时常放在句首：While I sympathize with your point of view I cannot accept it 尽管我认同你的观点，但我不能接受它。C when可以意为seeing thatalthough（鉴于）。因此它同while 很相似，但主要用于引导使另一个动作显得不合理的陈述句。它常用在一个问句里，但不是一定如此：How can you expect your children to be truthful when you yourself tell lies？ 你自己都在撒谎，怎么能指望你的孩子们诚实？Its not fair to expect her to do all the cooking when she has had no training or experience 她没有受过烹调方面的训练，也没有这方面的经验，让她把做饭的事全部承担下来是不公平的。D 请务必不要搞混when与if的用法。When he comes（等他来了）意为我们肯定他会来的。If he comes（如果他来了）意为我们不能肯定他是否会来