一、when“当……时”,引导时间状语从句时,从句用于表示主句动作发生的特定时间。如: The days get longer when spring comes. = When spring comes, the days get longer. 春天到来时,白天变得更长了。
二、before“在……之前”,引导时间状语从句时,表示主句动作发生在从句动作之前。如: Close the door before you leave the room. 离开房间前关上门。
三、after“在……之后”,引导时间状语从句时,表示主句的动作发生在从句的动作之后。如: I went to school after I finished my breakfast. 吃完早饭后我就去上学了。
四、as soon as“一……就……”,引导时间状语从句时,表示主句动作紧接着从句动作发生。如: I’ll call you as soon as I get home. 我一到家就给你打电话。
五、until, till“直到”,引导时间状语从句。当主句谓语动词是延续性动词时,主句常用肯定形式;当主句谓语动词是非延续性动词时,主句要用否定形式,即“not…until/till…”意为“直到……才……”。如: I’ll wait here until/till the rain stops. 我将在这里等着,直到雨停。 You can’t go home until/till you finish your work. 直到你完成你的工作,你才能回家。 下面再向大家透露点儿内幕消息,状语从句的两手绝活——时态的呼应和从句的位置。请看: 一、时态呼应 一般来讲,复合句都要遵循主、从句时态呼应规律,状语从句也不例外。即主句用现在时,从句也用现在时;主句用过去时,从句也用过去的某种时态。如: Be careful when you cross the road. 过马路时要小心。 You must see the doctor if you are ill. 如果你生病了,你必须去看医生。 主句是一般过去时,从句也要用一般过去时。如: When he was seven years old, he could swim. 当他七岁时就会游泳。 She turned off the light before she left the office. 她离开办公室前就关了灯。
二、主从句的位置。 大多数情况下,从句可以位于主句之前,也可以位于主句之后。不过从句在前时,主从句之间必须用逗号隔开。如: Please tell me when he comes back. = When he comes back, please tell me.
说到when引导的从句" data-id="link-to-so">时间状语从句,不得不提起as和while 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 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? 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。 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。 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。 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,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(指过去的事情)。 sb.had hardly(=scarcely) done sth.when...=Hardly / Scarcely had sb.done sth.when... ①I 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.我刚一闭上眼,就有人在敲门了。 ②I had hardly /scarcely entered my room when the telephone rang.=Hardly /Scarcely had I entered my room when the telephone rang.我刚一走进房门,电话就响了 |
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来自: 昵称30200765 > 《待分类1》