Question

while和when引导时间状语从句的区别

Answer 1

when表示“当……的时候”。从句中既可用延续性动词，又可用非延续性动词，这些动词既可以表示动作，又可表示状态。从句中的动作既可和主句的动作同时发生，又可在主句的动作之前或之后发生。
例如：Mary was having dinner when I saw her.
The boy was still sleeping when his mother got home yesterday morning.

　　　　　When the teacher came in, the students stopped talking.
while表示“在……的时候”、“在……期间” 、“一边……一边……”。while从句中必须是表示动作或状态的延续性动词。它强调主句的动作与从句的动作同时发生或主句的动作发生在从句的动作过程中。例如：The weather was fine while we were in Beijing.
She called while I was out.
I was drawing  brotreading.
He likes reading a newspaper while he is waiting for the bus.
如果主句的动作在从句的动作过程中发生，从句常用进行时。
例如：While we were swimming, someone stole our clothes.
Don't talk so loud while others are working.