1、.*;第 PAGE5 頁英語時間狀語從句講解when, while 和 as 引導時間狀語從句的用法一、when 的用法假如只從現象來看，when 從句用的最多的是一般過去時，而主句的時態沒有限制,根據詳細情況而定。1. When he was a child he was always trying out new ideas. 3. Were you writing when the teacher came in? 老師進來的時候，你在寫信嗎？4. Sorry, I was out when you called me. 對不起，你打 來的時候我出去了。when 從句的重點不在動作本身發

2、生的狀態，而只是把它作為一個時間點，所以when 多數情況下用的是一般過去時，那么不用正在進展時。因為假如用正在進展時，它表示的就是一段時間而不是一個時間點了。根據這一點，有的文章補充說：when 從句的動詞大多是瞬時動詞。這種說法也可以參照。實際上，when 從句也可以有其它的時態，但幾乎也不用進展時，因為它也只是作為一個時間參照點。例如：2. When he had finished his homework, he took a short rest.3. Why do you want a new job when you have got such a good one alread

3、y? 二、while 的用法相比于when 來說，while 從句的側重點就不一樣了。while 從句的側重點在于描繪動作正在發生的狀態，它的意思是：當while 事件正在發生的時候，另一件事如何如何。所以，while 從句一般用的是正在進展時。而另一件事的狀態沒有硬性的要求，根據詳細情況而定。例如：1. While my wife was reading the newspaper, I was watching TV. 2. While Jim was mending his bike, Lin Tao came to see him. 3. While they were talking

4、, the bell rang. 正在他們談話的時候，上課鈴響了。從時間的角度來看，while 表示的是一段時間，是一個過程。這是while 的側重點。因此，假如含有“一段時間的含義的時候，就可以用while。6. Strike while the iron is hot. 趁熱打鐵。這句話中，是說趁著鐵是熱的這段時間，趕緊打鐵。假如換成 when 意思就變了，相當于說鐵只熱了一下，打一下，然后鐵就冷了。這顯然不符合文意。再例：Im going to the post office. While youre there, can you get me some stamps? 三、as 的用法

5、as 從句表示的也是一件事情正在發生，另一件事也正在進展當中。但與 while 從句不同的是，as 從句用的一般不用正在進展時，而只是一般過去時。as 從句一般可以翻譯成“邊邊。例如：1. As my mother sang those old songs, tears ran down her cheeks. 2. The students took notes as they listened. 學生們邊聽課邊做筆記。3. As we talked on, he got more and more excited. as 表達的事件，往往只是主句動作發生的背景或條件時，as 只是一個次要的

6、時間說明，不像while 從句有強調 while 動作本身的意思。因此，as 常常翻譯成“隨著之意。例如：1. As the time went on，the weather got worse. 隨著時間的推移，氣候更加糟糕。2. The atmosphere gets thinner and thinner as the height increases. 3. As years go by，China is getting stronger and richer. 少數情況下，假如強調動作正在發生，as 從句也可以用正在進展時。這只能算是特例了。1. The sad mother sat

7、 on the roadside, shouting as she was crying. 2. As we were going out, it began to snow. 正當我們出門時，雪開場下起來。3. He came in as I was going to bed. 我正要上床睡覺，他進來了。四、when, while, as 的互換假如從句動作和主句動作同時發生，并且從句動作為延續性動詞時，when，while，as 可以互換使用。1. When /While /As we were dancing, a stranger came in. dance 為延續性動詞2. Whe

8、n /While /As she was making a phone call, I was writing a letter. make為延續五、比較while, when, as1as, when 引導短暫性動作的動詞。 例如：Just as / Just when / When I stopped my car, a man came up to me. 2當從句的動作發生于主句動作之前，只能用when 引導這個從句，不可用as 或 while。例如：When you have finished your work, you may have a rest. 3從句表示“隨時間推移連詞

9、能用as，不用when 或while。 例如： As the day went on, the weather got worse.二before和after引導的時間狀語從句Before是主句動作發生在從句的前面。注意before引導的從句不再用否認式的謂語，并且當before引導的從句位于主句之后，有時譯成“就，才。還要注意主句和從句之間的時間關系。當主句用將來時，從句總是用如今時；假如before引導的從句謂語用的是過去時，那么主句動詞多用過去完成時，這樣以便表達動作發生的先后。After表示主句動作發生在從句動作之后。主句和從句的動作的時間關系正好與before引導的從句相反。例如：

10、It will be four days before they come back. 他們要過四天才能回來。 After we had finished the work, we went home.從句用過去完成時，主句用一般過去時 比較until和till 的用法此兩個連詞意義一樣。肯定形式表示的意思是“做某事直至某時，動詞必須是延續性的。否認形式表達的意思是“直至某時才做某事。動詞為延續性或非延續性都可以。正確使用這兩個連詞的關鍵之一就在于判斷句中的動詞該用肯定式還是否認式。肯定句：I slept until midnight. 我一直睡到半夜時醒了。 Wait till I call

11、 you. 等著我叫你。在肯定句中可用before代替。例如：Lets get in the wheat before the sun sets.否認句：She didnt arrive until 6 oclock. 她直到6點才到。 Dont get off the bus until it has stopped. 公共汽車停穩后再下車。 區別：1until可用于句首，而till通常不用于句首。例如：Until you told me, I had heard nothing of what happened. 3until when 疑問句中，until要放在句首。例如： Until

12、when are you staying?你呆到什么時候？ Until next Monday.呆到下周一。 注意：否認句可用另外兩種句式表示。 4Not until在句首，主句用倒裝。 例如：Not until the early years of the 19th century did man know what heat is. Not until I began to work did I realize how much time I had wasted.5It is not until that. 例如：It was not until I began to work that

13、 I realized how much time I had wasted. 四巧辨before和until在日常英語教學中，我們遇到學生問這樣的一些問題： 1.He will spend six hours at his desk_he finishes his composition. A.beforeB.untilC.afterD.when 2.The bike hit the tree_I could get off. A.whenB.before C.whileD.until 3.I knocked at the door for more than five minutes_Mr

14、s white answered it. A.until B.when C.afterD.before 4.It was_yesterday_be_the secret. A.not until；that；knewB.until；when；knew C.not before；that；foundD.before；that；didnt find 怎樣才能清楚地解釋其選擇的原因，這就涉及到until與before的區別問題。 實際上，只要我們把握住兩者使用時本身的含義及主句動詞是終止性的，還是延續性的，肯定式，還是否認式兩大點，就能容易地解決這類問題。現詳細說明如下： 一、在以下情況下，兩者可互換

15、用，但含義略有不同。before表示“在之前的意思，強調時間先后關系；而until表示“直到才的意思，主句是肯定句那么表示主句動作的終止時間；主句是否認句那么強調主句動作的起始時間。 1.主句為否認式終止性謂語動詞。常見的動詞是open,start,leave,arrive,finish, stop等。例如： 1The noise of the street didnt stop until/before it was midnight. 2The children wont come back until/before it is dark. 3I didnt leave the lovel

16、y boy until/before his mother came home. 2.主句為肯定式、延續性謂語詞，這類動詞用stand,stay,talk,be,wait等。例如： 1He lived with his parents until/before he graduated from school. 2I will wait until/before he comes to my help. 3I shall stay heer until/before you come back. 二、在以下情況下，用before不用until。 1.主句這肯定式、終止性謂語動詞，只用befor

17、e。例： 1He fell asleep before I could take off his clothes. 2We arrived there before it atarted to rain. 2.主句謂語動詞強調動詞的緩慢性，只用before，常伴有時間段狀語或時間段暗示。例： 1It was quite some time before he found the elephant at all. 2We had walked a long way before we found some water. 3.假如強調從句謂語動作未發生，就發生主句謂語動作，只用before。常譯為

18、“未及，“不或“不等就。例： 1We can leave early in the morning before it gets too hot. 2I must write it down before I forget it. 3We do want to buy something now before prices go up. 4.表“與其說倒不如，“與其毋寧只用before。例： 1I would give up my job before Id agree to be dismissed. 2He will die of hunger before he will steal.

19、5.在某些特定句型中用before。例如： 1It was not long before the whole country rose up. 2It will probably not be long before they understand each other. 三、以下情況一般區別用until。 1.主句是持續性謂語動詞時，肯定、否認都可以，但意義完全不同。肯定表動作終止，而否認表動作開場。例如： 1We discussed the problem until/before he came back.2We didnt discuss the problem until he c

20、ame back.2.notuntil句型盡管在某些情況下可與before互換用，但在強調句中一般仍用until。 1It was not until he told me that I knew it. 2It was not until he finished his homework that he went home. 綜上所述，前面的4條選擇題中，第1、3題強調動作發生的緩慢性應選before。第2題表動作未及發生就發生主句動作也應選before。第4題為強調句應選A項。五其他時間狀語從句的用法1.由since引導的時間狀語從句。since引導的從句的謂語動詞可以是延續性的動詞，又可

21、以是瞬時動詞。一般情況下，從句謂語動詞用一般過去時，而主句的謂語動詞用如今完成時。但在It is 時間since從句的句型中，主句多用一般如今時。例如： I have been in Beijing since you left. 自從你分開以來，我一直在北京了。 It is five months since our boss was in Beijing.我們老板分開北京有五個月了。 知識擴展1. It is since從。以來多長時間了因為since +從句或名詞，表示一段時間It is five years since we met last time.從我們上次見面已經五年了。2. It is +before。才It was a long time before I went to sleep again.It was an hour beforeun