唐朝开放么:什么是时间状语从句？

after/before/when/while/as soon as/as/until...+一个陈述句,这样的就叫做时间状语从句.
时间状语从句表示一个时间,和其他时间不同在于,它是一个句子来表示时间.

时间状语从句：是由when, as, while, after, before, since, until, as soon as 等从属连词引导的状语从句。
时间状语从句中的谓语动词不能用一般将来时，只能用一般现在时表示将来发生的动作或存在的状态。如:I will call you as soon as I arrive there.
1. when引导的时间状语从句,常译为"当……的时候",when的从句可以用延续性动词,也可以用点动词.
eg.
He was working at the table when I went in . 当我进去的时候,他正在桌旁工作.
Someone knocked at the door when I was sleeping . 当我正在睡觉时,有人敲门.
I will visit my good friend when I have time . 当我有空儿时,我将去看望我的好友.
I worked for a foreign company when I was in Shanghai . 当我在上海时,我为一家外国企业工作.
注:when也可以作并列连词,表示一个动词正在进行的时候,突然间发生了另外一件事.
eg.
I was fishing by the river , when someone called for help .
我正在河边钓鱼,就在那时有人求救.
We were working in the chemistry lab , when the lights went out .
我们正在化学实验室工作,突然灯都熄灭了.
2. while引导的时间状语从句,常译为"与……同时,在……期间",while的从句中常用延续性动词或表示状态的词.
eg.
They rushed in while we were discussing problems .
当我们正在讨论问题时,他们冲了进来.
Father was cleaning the car while I was playing computer games .
当我正在打电子游戏时,爸爸正在清洗汽车.
注:while也可以作并列连词,表转折的关系,相当于but,译为"然而".
eg.
I like listening to music , while my brother likes doing sports .
我喜欢听音乐,而我的兄弟爱好运动.
3. as引导的时间状语从句,常译为"当……的时候,一边……一边"as的从句中可使用延续性动词,也可使用点动词.
eg.
He sang as he was working . 他一边工作一边唱歌.
As time goes by , we have a better understanding of things around us .
随着时间的推移,我们对自己周围的事物有了更好的理解.
4. before和after引导的时间状语从句,before强调主句的动作发生在从句的动作之前,而after强调主句的动作发生在从句的动作之后.
eg.
He had been a cook before he went to college . 他上大学前曾当过厨师.
He called me after he had finished his work . 他在工作完之后给我打了个电话.
注:若主句和从句两个动作发生的先后顺序十分接近,那么也可以不用完成时态,例如上面的第二句可改成:He called me after he finished his work .
5. as soon as引导的时间状语从句,译为"一……就……".
eg.
He will go to see you as soon as she gets here . 他一到这里就会去看你.
She got everything ready as soon as she got to school . 她一到学校就把一切都准备好了.
6. since引导的时间状语从句,译为"自从……",主句常用现在完成时,从句常用一般过去时.
eg.
We have made many dumplings since we began to cook .
自从我们开始做饭起,我们已经包了许多饺子了.
We haven't seen each other since we parted . 我们自从分手以后一直没见过面.
注:常用句型:It is +时间段+since从句 译为:自从……有多长时间了.
eg.
It is six years since she graduated from the university .
自从她大学毕业已有六年的时间了.
7. till和until引导的时间状语从句,译为"直到……为止",not … till / until引导的时间状语从句,译为"直到……才".前者强调主句动作的结束,用延续性动词,后者强调主句动作的开始,用点动词.
eg.
I will wait for my friend until / till he comes . 我要一直等到我朋友来.
We won't start our discussion until / till he comes .
我们要等到他来了,再开始我们的讨论.