8B过去进行时when-as和while的区别(课堂PPT).ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,when和while的区别,when,是at or during the time that,既指时间点，也可指一段时间；,while,是during the time that，只指一段时间，因此,when,引导的时间状语从句中的动词可以是终止性动词，也可以是延续性动词，而,while,从句中的动词必须是延续性动词。,when,说明从句的动作和主句的动作可以是同时，也可以是先后发生；,while,则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生。,1,由,when,引导的时间状语从句，主句用过去进行时，从句应用一般过去时；如果从句和主句的动作同时发生，两句都用过去进行时的时候，多用while引导，如：,a.,When,the teacher came in,we were talking.,当此句改变主从句的位置时，则为：,While,we were talking,the teacher came in.,b.They were singing,while,we were dancing.,when,和,while,还可作并列连词。when表示“在那时”；,while,表示“而，却”，表对照关系。如：,a.The children were running to move the bag of rice,when,they heard the sound of a motor bike.,孩子们正要跑过去搬开那袋米，这时他们听到了摩托车的声音。,b.He is strong,while,his brother is weak.,他长得很结实，而他弟弟却很瘦弱。,2,一、,when,可以和延续性动词连用，也可以和短暂性动词连用；而,while和as,只能和延续性动词连用。,Why do you want a new job,when,youve got such a good one already？（get为短暂性动词）你已经找到如此好的工作，为何还想再找新的？,Sorry，I was out,when,you called me（call为短暂性动词）对不起，你打电话时我刚好外出了。,Strike,while,the iron is hot（is为延续性动词，表示一种持续的状态）趁热打铁。,The students took notes,as,they listened（listen为延续性动词）学生们边听课边做笔记。,3,二、,when,从句的谓语动词可以在主句谓语动作之前、之后或同时发生；while和as从句的谓语动作必须是和主句谓语动作同时发生。,1从句动作在主句动作前发生，只用,when,。,When,he had finished his homework，he took a short rest（finished先发生）当他完成作业后，他休息了一会儿。,When,I got to the airport，the guests had left（got to后发生）当我赶到飞机场时，客人们已经离开了。,2从句动作和主句动作同时发生，且从句动作为延续性动词时，,when，while，as,都可使用。,When While As,we were dancing，a stranger came in（dance为延续性动词）当我们跳舞时，一位陌生人走了进来。,When While As,she was making a phonecall，I was writing a letter（make为延续性动词）当她在打电话时，我正在写信。,4,when 和while 的区别,When,的用法比较活，用在状语从句中，两边的时态可以,相等,.,1)He,was singing,when,I,was reading,.,2)Father,is cooking,when,Tom,is sleeping.,3)Please,say,hello to Mike,when,you,see,him.,5,when两边的时态也,可以不等,Kate,was swimming,when her parents,came,back.,They,were trying,to run away when the policeman,broke,into the house.,The light,went,off when they,were talking,.,6,while连接的句子，后面,必须用进行时,（现在/过去进行时）,A car hit her,while,she,was thinking,about a question.,The books fell off from the shelf,while,they,were listening,to the radio.,While,we,are playing,football,a noise comes from downstairs.,小结：用while 和when 填空，看看它们后面的句子的时态。如果是,过去,时，必须用,when,.如果是,进行,时，必须用,while,（没有while选项的时候用when),7,小结：在作,“当时候”,时，when可以替换while,.,Mary was happy,while/when,she was doing her homework.,When/while,they are watering flowers,a stranger shout at them.,While 还有,“然而”,的意思。此时不能用when 代替。,1）He has a good chance to be the famous player,while,he wasted it.,2)We could come to see the film yesterday,while,Tom lost the tickets.,8,用,while,和,when,填空,1）He was copying a text _ his brother came in.,2)Mary learnt a lot _ she was only 7.,3)_ I was drinking,father came in.,4)They bought many food _ Mike was studying.,5)_ the thief was stealing the DVD,a lot of people came in.,6)_ he fell down,he came up with an idea.,when,when,While/when,while/when,While/when,When,9,3当主句、从句动作同时进行，从句动作的时间概念淡化，而主要表示主句动作发生的背景或条件时，只能用 as。这时，as常表示“随着”；“一边，一边”之意。,As,the time went on，the weather got worse（as表示“随着”之意）,The atmosphere gets thinner and thinner,as,the height increases随着高度的增加，大气越来越稀薄。,As,years go by，China is getting stronger and richer随着时间一年一年过去，中国变得越来越富强了。,The little girls sang,as,they went小姑娘们一边走，一边唱。,The sad mother sat on the roadside，shouting,as,she was crying伤心的妈妈坐在路边，边哭边叫。,10,4在将来时从句中，常用when，且从句须用一般时代替将来时。,You shall borrow the book,when,I have finished reading it在我读完这本书后，你可以借阅。,When,the manager comes here for a visit next week，Ill talk with him about this下周，经理来这参观时，我会和他谈谈此事。,11,as,when,while都表示主、从句的动作或状态同时发生，但三者意义不尽相同。as和when引导的从句既可表示一点时间，也可表示一段时间，从句中的谓语动词既可以是持续性动词，也可以为短暂性动词，经常可以互换使用；while引导的从句通常表示一段时间，从句中宜用持续性动词作谓语。当从句中的谓语动词为持续性动词时，这三者可以通用（前面例句中已有体现），再如：,Mother was worried because little Alice was ill,especially,as/when/while,father was away in France.妈妈担心，因为小艾丽思病了，特别是当父亲远在法国的时候。,如果从句和主句要表示一个人的两个动作交替进行或同时完成时，则多用as，可译为“一边.，一边.”。例如：,He looked behind from to time,as,he went.他一边走，一边不时地往后看。,As,time goes on,its getting warmer and warmer.随着时间的推移，天气变得越来越暖了。,I thought of it just,as,you opened your mouth.你一张嘴我就知道你要说什么。（若表示两个短促动作几乎同时发生时，用as的场合多于when.）,12,当主从句之间表示转折或对比关系时，多用while,不用as或when。如：,She thought I was talking about her daughter,while,in fact,I was talking about my daughter.她以为我在谈论她女儿，而事实上，我在谈论我的女儿。,如果表示从句的动作在主句的动作“之前”或“之后”发生时，多用when（=after）,不用as或 while。此外，when还含有“at that moment”的意思（=and then），引起的句子不能放在句首，也不能用as,while来替换。例如：,He was about to leave,when,the telephone rang.他正要离开，忽然电话铃响了。,We were watching TV,when,suddenly the lights went out.我们正在看电视，突然灯灭了。,They had just arrived home,when,it began to rain.他们刚到家，天就开始下雨了。,13,as soon as,的用法,as soon as,连接的时间状语从句中，指,未发生的动作,，规律是：主句一般将来时，从句用一般现在时代替一般将来时（,主将从现,）,I,will tell,him the news as soon as he,comes,back。,They,will be,crazy as soon as they,hear,the news,As soon as he,gets,home,he,will notice,you.,14,指紧接着发生的两个短动作，主从句都用一般过去时,1)He,took,out his English books as soon as he,sat,down,2)We,ate,a lot as soon as we,got,home.,3)As soon as she,came,out of the house,she wore a big hat.,小结：看as soon as 的时态，要么两边都是过去时，要么就是主将从现,15,填空,He _(fly)to America as soon as he _(be)free.,We _(let)you know as soon as the result _(come)out.,They _(do),moring,exercises as soon as they _(get)up.,As soon as Mary _(turn)on TV,she _(begin)to eat,sth,.,Bob _(start)to cry as soon as he,_(see)his mother.,will fly,is,will let,comes,will do,get,turned,began,start,saw,16,