一、while作名词用,表示“一会儿,一段时间”
She likes to lie down for a while after lunch.
她喜欢午饭后躺一会儿.
二、While作连词
(1)引导时间状语
While she was listening to the radio ,she fell asleep.
她听着收音机睡着了.
2)引起让步状语从句,意思是“虽然…但是….”、“尽管…但是…”(多放于句首)
While he loves his students ,he is very strict with them..
虽然他爱他的学生,可是他对他们很严格.
3)引起条件状语,意思是“只要”
While there is life there is hope.只要生命存在,就有希望
三、While作并列连词用,意思为“而,然而”,表对比.
Some people waste food while others haven't enough. 有些人很费粮食,然而有些人却吃不饱.