8B过去进行时when,as和while的区别

• 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。
• 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, it’s 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.）
• ③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. • ④when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。
• 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。
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.
when 和while 的区别
1. 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.
when两边的时态也可以不等 1) Kate was swimming when her parents came back. 2) They were trying to run away when the policeman broke into the house. 3) The light went off when they were talking.
• 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。 • ①When 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。 • ②When 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。 • ①When ／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。 • ②When ／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。
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
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)
小结：在作“当…时候”时，when可以替换 while. 1) Mary was happy while/when she was doing her homework. 2) 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.
when和while的区别
• ①when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。 • ②when 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。
2) We could come to see the film yesterday while Tom lost the tickets.
用while 和when填空
when 1）He was copying a text _______ his brother came in. when 2) Mary learnt a lot ______ she was only 7. While/when 3) __________ I was drinking, father came in. while/when 4) They bought many food __________ Mike was studying. While/when 5) __________ the thief was stealing the DVD, a lot of peopቤተ መጻሕፍቲ ባይዱe came in. 6) ______ he fell down, he came up with an When idea.
• 4．在将来时从句中，常用when，且从句须用一般 时代替将来时。 • ①You shall borrow the book when I have finished reading it．在我读完这本书后，你可 以借阅。 • ②When the manager comes here for a visit next week，I’ll talk with him about this．下周，经理来这参观时，我会和他谈谈此 事。
while连接的句子，后面必须用进行时（现在/ 过去进行时） 1) A car hit her while she was thinking about a question. 2) The books fell off from the shelf while they were listening to the radio. 3) While we are playing football, a noise comes from downstairs.
• 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。 • ① As the time went on，the weather got worse．（as表示“随着……”之意） • ② The atmosphere gets thinner and thinner as the height increases．随着高度的增加，大气越来越稀薄。 • ③As 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。 • ④The little girls sang as they went．小姑娘们一边 走，一边唱。 • ⑤The sad mother sat on the roadside，shouting as she was crying．伤心的妈妈坐在路边，边哭边叫。
• 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。 • ① Why do you want a new job when you‘ve 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？ • ②Sorry，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。 • ③Strike 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。 • ④ The students took notes as they listened．（listen为延续性动词）学生们边听课 边做笔记。