另外while还有别的用法,while引导状语从句,有以下两种含义:
1.表示某个动作正在进行的同时,另一动作也在进行之中,这时主从句都用进行时态,有对同类的两个动作进行对比的意味.如:
While I was playing the piano,she was dancing.我在弹钢琴,她在跳舞.
While Jim is picking apples,Kate is carrying apples to the truck.吉姆正在摘苹果,凯特正在把苹果搬到卡车上去.
2.表示某个动作正在进行时,又发生了另一动作(该动作用一般过去时).如:
While I was reading,I fell asleep.我读着读着就睡着了.
While we were swimming in the river,we saw a fish jump out of the water.我们正在河中游泳时,看见一条鱼跃出了水面.