as when 用法区别

文/叶丹

when、as引导时间状语从句时,侧重点有所不同:when可指时间点,又可指时间段,从句中可用延续性动词,也可用非延续性动词。as多用于平行结构,表示两个动作同时发生:一个主语同时进行两个动作;一种状态随另一种状态的变化而变化。表示主句的动作发生在从句的较长动作过程中,when、as均可使用。从句中为be动词时,多用when。

as when 用法区别

as,when和while的区别

1. As/When/While:A was happening, B happened或B happened as/when/while A was happening.

as,when,while用来表示“当某事发生的时候,一个长的行为或事件正在进行”。

当从句引导的句子表示持续性动作时,as/when/while引导的从句一般用过去进行时(was/were+动词ing)。例如:

As I was walking down the street I saw Joe driving a Porsche.当我正在沿着街道走的时候,我看到乔正开着保时捷。

The telephone rang when i was having a bath 当我正在洗澡的时候,电话铃响了。

as,when,while都可以用现在时态,如:

Please don't interrupt me when I'm speaking.当我说话的时候,请不要打断

I often get good ideas while I'm shaving.当我刮胡子的时候,我经常能想到好点子。

2. while A was happening,B was happening或While A happened, B happened

while用来表示两个长动作或事件过去同时发生,用过去进行时或者过去时态。如:

While you were reading the paper ,I was working.当你在读报纸的时候,我正在工作。

John cooked supper while I watched TV.当约翰在煮晚饭的时候,我在看电视。

也可以用现在时态,如:

After supper,I wash up while Mary puts the children to bed.晚饭后,当玛丽弄孩子们睡觉的时候我在洗漱。

3. As A happened,B happened.

B happened,as A happened.

as,when和while的区别

as 用在两个短的行为或事件同时发生,如:

As I opened my eyes I heard a strange voice.当我睁开眼睛的时候,我听到奇怪的声音。

The doorbell rang just as i picked up the phone.当我拿起电话的时候,门铃响了。