时间状语从句-用法

时间状语从句-用法        
      1.由when, while, as引导的时间状语从句。 
   When you think you know nothing, then you begin to know something.当你以为自己一无所知的时候，你就是在开始知道一些事物了。
When truth is buried under the ground it grows, it chokes, it gathers such an explosive force that on the day it bursts out , it blows up everything with it.当真理被埋在地下的时候，它在生长，它感到压抑，它蓄存着这么一种爆炸性力量，一旦冒出，它就会炸破一切！  
      注意：when, while和as的区别：when引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。并且when有时表示“就在那时”。 
      When she came in, I stopped eating.她进来时，我在吃饭。 
      When I lived in the countryside, I used to carry some water for him.      当的住在农村时，我常常为他担水。 
      We were about to leave when he came in.我们就要离开，就在那时他进来了。 
      While引导的从句的谓语动作必须是延续性的，并强调主句和从句的动作同时发生（或者相对应）且   while有时还可以表示对比。
While my wife was reading the newspaper, I was watching TV. (was reading是延续性的动词，was reading和was watching同时发生)
I like playing football while you like playing basketball.我喜欢踢足球，而你喜欢打篮球。
As表示“一边……一边”，as引导的动作是延续性的动作，一般用于主句和从句动作同时发生；as也可以强调“一先一后。
We always sing as we walk.我们总是边走边唱。
As we was going out, it began to snow.当我们出门时，开始下雪了。（as强调句中两个动作紧接着先后发生，而不强调开始下雪的特定时间）
2.由before和after引导的时间状语从句。注意before引导的从句不再用否定式的谓语，并且当before引导的从句位于主句之后，有时译成“就，才”。还要注意主句和从句之间的时间关系。当主句用将来时，从句总是用现在时；如果before引导的从句谓语用的是过去时，则主句动词多用过去完成时，这样以便体现动作发生的先后。After表示主句动作发生在从句动作之后。主句和从句的动作的时间关系正好与before引导的从句相反。如：
It will be four days before they come back. 他们要过四天才能回来。 
After we had finished the work, we went home.完成工作之后，我们回家了。（从句用过去完成时，主句用一般过去时）
3.由till或until引导的时间状语从句。till和until一般情况下两者可以互换，但是在强调句型中多用until。并且要注意的是：如果主句中的谓语动词是瞬时动词时，必须用否定形式；如果主句中的谓语动词是延续性动词时，用肯定或否定形式都可以，但表达的意思不同。如：
I didn't go to bed until（till） my father came back.直到我父亲回来我才上床睡觉。
It was not until the meeting was over that he began to teach me English.直到散会之后他才开始教我英语。
Please wait until I arrived.在我到达之前请等我。
4.由since引导的时间状语从句。 since引导的从句的谓语动词可以是延续性的动词，又可以是瞬时动词。一般情况下，从句谓语动词用一般过去时，而主句的谓语动词用现在完成时。但在It is ＋时间＋since从句的句型中，主句多用一般现在时。
I have been in Beijing since you left. 自从你离开以来，我一直在北京了。
Where have you been since I last saw you? 自上次我和你见面以后，你到哪里去了？
It is four years since my sister lived in Beijing. 我妹妹不在北京住有四年了。
It is five months since our boss was in Beijing.我们老板离开北京有五个月了。
5.由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引导的时间状语从句。这些连词都表示“一……就”。
I will go there directly I have finished my breakfast. 吃完早饭，我立即到那里去。
The moment I heard the news, I hastened to the spot.我一听到消息，马上赶到了出事地点。
As soon as I reach Canada, I will ring you up. 我一到加拿大，就给你来电话。
注意：hardly(scarcely, rarely)…when / before, no sooner…than相当于as soon as之意。主句用过去完成时，从句用一般过去时。当hardly, scarcely, rarely和no sooner位于句首时，主句应用倒装语序。
He had no sooner arrived home than he was asked to start on another journey. 他刚到家，就被邀请开始另一旅程。
No sooner had the sun shown itself above the horizon than he got out of bed to commence work.太阳刚从地平线上升起，他就起床劳动去了。
Hardly had I sat down when he stepped in.我刚坐下，他就进来了。
He had hardly fallen asleep when he felt a soft touch on his shoulder.这个阿拉伯人刚要入睡就感到肩膀上被轻轻一触。
6.由by the time引导的时间状语从句。注意时态的变化：在一般情况下，如果从句的谓语动词用一般过去时，主句的谓语动词用过去完成时；如果主句的谓语动词用一般现在时，主句的谓语动词用将来完成时。如：
By the time you came back, I had finished this book.到你回来时，我已经写完这本书了。
By the time you come here tomorrow, I will have finished this work. 你明天来这儿的时候，我将已经完成此工作了。
7.由each time, every time和whenever引导的时间状语从句。
Each time he came to Harbin, he would call on me. 他每次来哈尔滨，总是来看我。
Whenever that man says“To tell the truth”, I suspect that he's about to tell a lie.每当那个人说“说实在话”的时候，我猜想他就要说谎了。
You grow younger every time I see you. 每次遇到你，见你更年轻了。
8.由as long as和so long as引导的时间状语从句。这两个连词表示“有多久……就多久”。
You can go where you like as long as you get back before dark. 你可以随意到哪里去，只要在天黑以前回来就行。 时间状语从句-时间状语       
时间状语从句一般现在时 every …, sometimes, at …, on Sunday, 一般过去时 yesterday, last week, an hour ago, the other day, in 1982, just now 一般将来时 next…, tomorrow, in+时间, 现在完成时 for, since, so far, ever, never, just, yet, till/until, up to now, in past years, always, recently 过去完成时 before, by, until, when, after, once, as soon as 过去进行时 this morning, the whole morning, all day, yesterday, from nine to ten last evening… when, while 将来进行时 soon, tomorrow, this evening, on Sunday, by this time, tomorrow, in two days, tomorrow evening 时间状语从句-从属连词       
时间状语从句引导时间状语从句的普通类从属连词有when（当……时），while（在……期间），as（当……，一边……一边……），before（在……之前），after（在……之后），since（从……以来），till/until（直到），whenever（无论何时），as soon as（一……就）等。如：
When I went into the classroom, he was reading. 当我走进教室时，他正在看书。
He read a newspaper as he went along. 他边走边看报纸。
We must strike while the iron is hot. 我们必须趁热打铁。
I will tell you after they leave. 于他们走后我再告诉你。
I told him to come back whenever he wants to. 我告诉他什么时候想回来就回来。
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
注意：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。时间状语从句-一词多义       
时间状语从句一、对before从句的理解
before的本意为“在……之前”，根据具体语境还可理解为“还没来得及/还没有……就……，趁着还没……就……，不知不觉就……，……才……”等。如：
I had not sat long before he came back. 我没坐多久他就回来了。
He almost knocked me down before he saw me. 他几乎把我撞倒才看到我。
Before I could get in a word, he measured me. 我还来得及插话，他就给我量好了尺寸。
I’ll water the flowers before it gets dark. 我要趁着天还没黑把花浇好水。
Be a pupil before you become a teacher. 先做学生，后做先生。
Time passed quickly and three months went by before she knew it. 时间过得飞快，她不知不觉就在那里度过了三个月I will die before I will betray my country. 我宁可死也不会背叛我的国家。
二、对since从句的理解
1. since从句的谓语动词是终止性动词照字面意思理解。如：
I’ve been feeling down since I lost my job. 自从失去工作后,我的情绪一直处于低潮。
2. since从句谓语动词延续性动词，且为现在完成时时，仍然按字面意思理解。如：
She has never come to see me since I have lived in the city. 自从我住到城里，她就一直不来看我。
3. since从句谓语动词延续性动词，且为一般过去时时，按与字面意思相反的意思理解。如：
I have made great progress since I was ill. 我自病愈以来取得了很大的进步。
4. since前有ever，或从句谓语动词是be且后接表示人成长过程中的某个阶段或年龄的名词、形容词时，仍然按字面意思理解。如：
I have lived here ever since I was a child. 我从还是个孩子时就一直住在这儿。
三、对till/until从句的理解
1. 主句为肯定式，主句谓语动词必须为持续性动词，且该动词所表示的动作或状态一直延续到until/till从句所表示的时间为止，可译作“（直）到……”。如：
He waited until/till I returned. 他一直等到我回来。
2. 主句为否定式（包括含no, nobody, nothing, never, hardly, little等否定词的肯定句），若主句谓语动词是非持续性动词，则该动词所表示的动作在until/till从句表示的时间开始发生。一般先译从句“直到……”，后译主句，not 译成“才”，即“直到……才……”。如：
 His mother didn’t leave until/till he was asleep. 直到他睡着了，他母亲才离开。
Nobody can leave until/till the meeting is over. 直到散会才能离开。
3. 主句为否定式，若主句谓语动词是持续性动词，则须根据上下文去理解until/till从句的含义，一般译为“直到……才……”或“没有到……”。如：
He didn’t wait until/till I returned. 他没有等到我回来。
She didn’t sleep until/till I returned. 她直到我回来才睡着。时间状语从句-与强调句对比       
时间状语从句强调句的句型是：
It is (was) 被强调部分+ that (who) + 句子其他部分
第一句是对的，后面一句是错的。
It was seven o'clock when we reached the station.（状语从句）
=It was "at" seven o'clock "that" we reached the station.(强调句，定语从句） 强调句和时间状语从句的区别是：时间状语从句可以去掉，不影响句子的完整性。而强调句that/who引导的句子是不能去掉的，否则句子就不完整了，单独的“It was at seven o'clock”是错误的。 时间状语从句和定语从句的区别其实跟上面说的是一样的，强调句型其实就是一种特殊的定语从句。本身最简单的表达法是：We reached the station at seven o'clock.然后为了强调"at seven o'clock",就变成了强调句It was "at seven o'clock" that we reached the staion，同时它也是定语从句：从句“that we reached the staion”修饰的是it=the time. 时间状语从句-时态问题       
时间状语从句时间状语从句常用的连词有：when，as，while，before，after，since，till，until，as soon as，once。 【例】 Before I could get in a word, he already gave orders. 我还来不及插话，他已经吩咐下去了。 After the students were all in the lab, the professor brought out three bottles. 在学生们全进入实验室后，教授拿出三个瓶子来。 学习时间状语从句应注意以下几点： （1）时间状语从句中一般不使用将来时态，尽管主句使用将来时态，一般使用一般现在时态或现在完成时态。 【例】 I'll go on with the work when I come back tomorrow. 我明天回来，我将继续做这项工作。 Please tell him about it when you see him back. 你看到他回来，就告诉他这件事。 （2）till/until引导时间状语从句，主句的谓语动词如是延续动词，可使用否定或不用否定，如果是不延续动词，必须使用否定形式。 【例】 He didn't go to bed until it was 12 o'clock last night. 他昨晚十二点才上床睡觉。 They worked until it was dark. 他们一直工作到天黑。 （3）as soon as, the moment, every time, each time, the minute, the instant, the day, the week, the year, the first time,next time, any time, the last time, all the time, from the time, by the time, immediately, instantly, directly等表示时间的词语，后面也可以接时间状语从句，表示“一……就……”。 【例】 I recognized you the minute I saw you. 我一见到你，就认出了你。 By the time he was fourteen, he had built his own lab. 到他十四岁的时候，他已建起自己的实验室。 （4）主句使用过去进行时或过去完成时，或是was/were about to do Sth. ,后面从句使用when从句，而且谓语动词使用一般过去时，这时when不当“当……时候”解，而当“突然”解。 【例】 They were working in the fields when it began to rain. 他们在地里正干着活时，天突然下起雨来。 He was about to leave when the telephone rang. 他刚要走，突然电话铃响了。