从句中的谓语动词表示瞬间动作时,不可用while。 He was on the point of leaving when someone knocked at the door. 他正要走,这时有人敲门。 如果谈论两个长动作,最常用的是while。 While John was sitting biting his nails, I was working out...
when和while的区别 ①when是at or during the time that, 既指时间点,也可指一段时间; while是during the time that,只指一段时间,因此when引导的时间状语从句中的动词可以是终止性动词,也可以是延续性动词,而while从句中的动词必须是延续性动词。 ②when 说明从句的动作和主句的动作可以是同时,也可以...