1、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whil
2、e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。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。1、While they were talking,the bell rang.正在他们谈话
3、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,注意:1)如主句谓语动词表示的是短暂动作,从句时间状语指一段时间,when while as 三者可通用。Peter came in while/as I was watching TV.当Peter进来的时候我正在看电视。I was watching TV when Peter came in.当Peter进来时我正在看电视。2)as 和 when 可与非延续性动词连用,而 while
4、只能与延续性动词连用。He came in when/as I was going to bed.我正要上床睡觉,他进来了。3)as 和 while可用来指一段时间,但 as 强调主句与从句表示的动作同时发生,while强调主句表示的动作是在 while 从句的动作延续中发生。As my mother sang those old songs,tears ran down her cheeks.当我妈妈唱起那些老歌时,眼泪顺着她的脸颊流了下来。I came in while he was reading an interesting book in his room.,1.while后面跟时间段,when后面可跟时间点或时间段(一般跟时间点).2.while中主从句动作必同时发生,when中主从句动作可不同时发生.3.while中谓语动词必用延续性动词,when中可用延续性或瞬间性.4.while可表示转折,when不行.,