……………………………………………………………最新资料推荐…………………………………………………引导时间状语从句的五类引导词一．引导时间状语从句的从属连词(以下称引导词)很多，为方便记忆，现作以下分类：1. 基本类包括before, after, when, while, as, since, till, until, once, as soon as 等。
如：Did anyone call when I was out? 我不在家时谁来过电话吗?We have known each other since we were children. 我们从小认识。
You’ll feel better after you take the pills. 吃完药丸后你会感到好一些。
Make sure that all the lights are off before you go to bed. 睡觉前一定要关灯。
Don’t promise him anything till we’ve had time to think about it.在我们有时间考虑之前别答应他什么。
2. 名词类即由名词词组充当引导词，包括the moment, the minute, the second, the instant 等(均表示“一……就……”。
如I loved you the instant (that) I saw you. 我一见到你就爱上你了。
Tell me the moment (that) you get the results. 你一拿到结果就给我打电话。
3. 副词类即由副词充当引导词，如immediately, directly, instantly等。
如：I came immediately you called. 你一打电话我就来了。
Directly I walked in the door I smelt smoke. 我一进门就闻到烟味。
4. 短语类主是几个涉及time短语，如every time，each time，(the) next time，any time，the last time，the first time 等。
如：Next time you come in, please close the door. 下次你进来，请关门。
My roof leaks every time it rains. 每次下雨，我的房顶就漏。
He felt nervous each time she spoke to him. 每次她和他讲话，他都感到紧张。
The last time we talked he said he needed another two days. 上次我们谈话时他说他还需要两天。
5. 句型类包括no sooner…than, hardly…when 等。
如：I had no sooner closed the door than somebody knocked. 我刚把门关上就有人敲门。
Hardly were the words uttered when he began to regret them. 话刚说出口他就开始后悔了。
二．时态呼应在时间状语从句中，不能用一般将来时、过去将来时态或将来完成时，而要用相应的一般现在时态、一般过去时或现在完成时来代替。
如：I’ll telephone you as soon as I get there. 我一到达那里就打电话给你。
She said she would phone me as soon as she got there. 她说她一到达那里就给我电话。
Don’t get off the bus until it has stopped. 等车停稳后才下车。
……………………………………………………………最新资料推荐…………………………………………………I will tell you after they leave. 于他们走后我再告诉你。
I waited till/until she was back. 我一直等到她回来Once time is gone, you will never get it back. 时间一旦失去就再也得不到了1. 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。
■与时间状语从句有关的时态问题关于这个问题有两点值得注意：(1)当主句为将来时态或具有将来意义时，时间状语从句通常要用一般现在时表示将来意义，而不能直接使用将来时态：Turn off the lights before you leave. 走前关灯。
I will tell him as soon as he arrives. 他一来我就告诉他。
(2)与since 从句搭配的主句的时态通常是现在完成时态：He has lived here since 1999. 自1999年以来，他就一直住在这儿。
Where have you been since I last saw you? 自我上次见到你之后你到哪里去了?【注】在特定的语言环境中有时也可能用过去完成时或一般现在时：It seems like years since we last met. 我们似乎几年未见面了。
Yesterday he told me that he hadn’t eaten anything since Tuesday. 他昨天告诉我自星期二以来他一直未吃任何东西。
2. 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.三．基本类（一）. when, while, as的用法when只能用于一般时态，while可以用于进行时态while从句中的谓语动词必须是延续性动词；表示带有规律性的“每当”或当主、从句谓语动词的动作发生有先后时，只能用when；当表示“一边…一边…”或“随着”时，只能用as。
另外，用于此义的as 所引导的时间状语从句谓语只能是动作动词，不能是状态动词。
例题：_____ John was watching TV, his wife was cooking.A. AsB. As soon asC. WhileD. Till……………………………………………………………最新资料推荐…………………………………………………第一次描述：三者可表示“当……时候”，区别如下：(1) 若主句表示的是一个短暂性动作，从句表示的是一个持续性动作，三者都可用：He fell asleep when [while, as] he was reading. 他看书时睡着了。
【注】as 用于引出一个持续性动词表示“在……期间”时，其谓语通常只能是那些含有动作(action)和发展(development) 意味的动词，一般不能是那些不用于进行时态的动词(如be, seem, love, want, agree, see, know, have 等)，所以下面一句中的while 不能换为as：A：I’m going to the post office. 我要去邮局。
B：While you’re there, can you get me some stamps?当你在邮局时，能帮我买几张邮票吗?(2) 若主、从句表示两个同时进行的持续性动作，且强调主句表示的动作延续到从句所指的整个时间，通常要用while：Don’t talk while you’re eating. 吃饭时不要说话。
I kept silent while he was writing. 在他写的时候，我默不作声。
但是，若主从句表示的两个同时进行的动作含有“一边…一边”之意思，通常用as：She sang as she went along. 她边走边唱。
(3) 若从句是一个短暂性动作，主句是一个持续性动作，可用as / when 但不用while：It was raining hard when [as] we arrived. 我们到达时正下着大雨。
(4) 若主从句表示的是两个同时(或几乎同时)发生的短暂性动作，用as / when：I thought of it just when [as] you opened your mouth. 就在你要说的时候，我也想到了。
(5) 若要表示两个正在发展变化的情况，相当于汉语的“随着”，一般用as：Things are getting better and better as time goes on. 随着时间的推移，情况越来越好。
As it grew darker, it became colder. 天色越晚，天气越冷。
(6) 表示“每当…的时候”(暗示一种规律性)，一般要用when：It’s cold when it snows. 下雪时天冷。
He smiles when you praise him. 你夸奖他时他总是笑笑。
(7) 若主从句所表示的动作不是同时发生，而是有先后顺序时，一般要用when：I will go home when he comes back. 他回来时，我就回家去。
(8) when 可用作并列连词，表示“这时(突然)”；while 也可以用作并列连词，表示“而”、“却”(表示对比)；但as 则没有类似用法：We were about to start when it began to rain. 我们正要出发，这时天开始下雨了。
He likes coffee, while she likes tea. 他喜欢咖啡，而她却喜欢茶。
(9) as 和when 后均可直接跟一个名词，构成省略句，但while 一般不这样用：As [When] a boy, he lived in Japan. 他小时候在日本。