1、UNIT 3 Our Hobbies TOPIC 2 What sweet music! Section C -when引导时间状语从句,一、when可以和延续性动词连用，也可以和短暂性动词连用,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？ When I was doing my homework, my mother came. (was doing 为延续性动词） 当我在作业的时候，我妈妈进来了。,二、when从句的谓语动词可以在主句谓语动
2、作之前、之后或同时发生,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.
3、（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 phone call, I was writing a letter. （make为延续性动词）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.（as表示“随着”之意） 随着时间的转移，天气变得越来越糟。, The atmosphere gets t
4、hinner 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。,4在将来时从句中，常用when，且从句须用一般时代替将来时。When the manager comes here for a visit next week，Ill talk with him about this. 下周，经理来
5、这参观时，我会和他谈谈此事。,三、when用于表示“一就”的句型中（指过去的事情）。 Sb. had hardly / scarcely done sth when. Hardly / Scarcely had sbdone sth when.,我刚一闭上眼，就有人在敲门了。 I had hardly /scarcely closed my eyes when someone knocked at the door. Hardly / Scarcely had I closed my eyes when someone knocked at the door.,1. We will stay
6、at home if my aunt _ to visit us tomorrow.A. comes B. come C. will come D. is coming2. Ill go swimming with you when I _ free tomorrow. A.will be B. shall be C. am D. was,A,C,即时练习：,4. When he got to the station, the train _. A. left B. had left C. leaves D. has left5.We _ TV when the telephone _.A. watched; was ringing B. were watching; rang C. watch; rings D. are watching; rang,D,B,即时练习：,Thank you!,
