时间状语从句引导词.docx

时间状语从句引导词when，while，as引导时间状语从句的区别 when，while，as显然都可以引导时间状语从句，但用法区别非常大。 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？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对不起，你打电话时我刚好外出了。 Strike while the iron is hot趁热打铁。 The students took notes as they listened学生们边听课边做笔记。 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当他完成作业后，他休息了一会儿。 When I got to the airport，the guests had left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当她在打电话时，我正在写信。 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 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。 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。 三、when用于表示“一就”的句型中。 sbhad hardly done sthwhenHardly Scarcely had sbdone sthwhen I had hardly scarcely closed my eyes when someone knocked at the doorHardly Scarcely had I closed my eyes when someone knocked at the door我刚一闭上眼，就有人在敲门了。 I had hardly scarcely entered my room when the telephone rangHardly Scarcely had I entered my room when the telephone rang我刚一走进房门，电话就响了。 总结： when即可引导一个持续性动作，也可引导一个短暂动作，可用于主句和从句动作同时发生或从句动作先于主句动作。 while引导的动作必须是持续性的，侧重主句动作和从句动作相对比。 as soon as引导的从句都表示从句的动作一发生，主句的动作随之发生。常翻译为“一······就”。 before引导的从句，常翻译为还······就······；不到······就······。 until引导的从句主语谓语动词必须是非延续性动词，从句为肯定式。 after引导的从句，常翻译为:在······之后才······。