When用法小结.doc

When 用法小结 雒喜彪when是中学英语教材中应该掌握的重点词汇之一，词性较多，词义丰富。when的用法在高考中也是重现率较高的语言点。现将when的常见用法归纳如下。一、when做副词用时，意思是“什么时候”、“何时”。1 做疑问副词（=at what time），引导特殊疑问句。如：When did the train leave? 火车什么时候开走的？When are you going to Beijing? 你打算何时去北京？2 做联系副词（=at the time that），引导名词性从句。如：When they come is uncertain. 他们何时来未定。I asked him when the football match began. 我问他足球赛什么时候开始。3 做关系副词（=on or at which time），“当的时候”引导定语从句。如：Ill never forget the day when I met him. 我永远不能忘记碰见他的那一天。Tell me the time when the plane takes off. 请告诉我飞机起飞的时间。二、when做连词用时，可做从属连词，也可做等立连词。1 做从属连词，引导时间状语从句，除表示时间外，还可转做条件和让步连词等。（1）when（=at or during the time that）“当时”。如：It was raining when he arrived at the station. 当他到达车站时，正在下雨。When going out for a walk，I met an old friend. 我出去散步时，碰见一位老朋友。（2）when（=if）“如果”。如：Turn off the switch when anything goes wrong with the machine. 如果机器发生故障就把电门关上。Ill be here to give you help when it is necessary. 如果有需要，我帮助你。（3）when（=although or even though）“虽然”、“可是”。如：He usually walks when he might ride. 虽然有车可坐，他通常总是步行。They kept trying when they must have known it was hopeless. 他们明明知道那事没有希望了，但他们还继续在干。（4）when（=as soon as, the moment ）“一就”。如： I was just going out when the bell rang. 我刚要出去，铃就响了。Well start when they come. 他们一来，我们就出发。（5）when（=since, considering that）“既然”，“考虑到”。如：Why do you want a new job when youve got such a good one already?既然你已经有了这么好的一份工作，你为什么还要找新的工作？（6）when（=after the time that）“之后”、“以后”。如：When I finish my composition I will read it to you. 我写完作文后，读给你听。They continued their work when the rain had passed. 雨过去了，他们又继续 工作。（7）when（=whenever, at any time that）“每当”、“不论的时候都”。如：He brings a present when he comes. 他每次来都带着礼物。When we meet with difficulties, they come to help us. 当我们有困难时，他们总来帮我们。2 做等立连词，连接两个并列从句，when前用逗号分开，应把when看做是说明前一分句的时间，译做“在那时”或“突然”等。（1）when（=and then, at that time）“那时”、“当时”、“然后”。如：I stayed till noon, when I went home. 我呆到中午，然后就回家。We played outside for a while, when it began to rain. 我们在外面玩了一会儿，那时天下起雨来了。（2）when（=and just then, and at this time）“正当”、“忽然”。如：We were about to start, when it began to rain. 我们正要出发，忽然下起雨来了。We were watching TV, when suddenly the light went out. 我们正在看电视，灯突然熄了。三、when做代词（what time, which time）“什么时候”、“何时”、“此时”。如：Since when has he had a beard? 他从什么时候开始留胡子的？Till when can you stay? 你能呆到什么时候？四、when做名词（=the time, the date）。如：He told me the when and the how of it. 他把