过去进行时一 概念：过去进行时主要表示过去某个时刻或某一阶段正在进行的动作，常和表示过去的时间状语then，at that time/ moment， yesterday，at nine，last night等连用或者与when, while, as引导的过去时间状语连用。但在不少情况下，没有表示时间的状语，这时需要通过上下文来表示。We were watching TV from seven to nine last night. What was he researching all day last Sunday? 二过去进行时的主要用法是描述一件事发生的背景；一个长动作发生的时候，另一个短动作发生（长动作用过去进行时，短动作用一般过去时）。也可以表示两个动作同时发生，此时均用过去进行时When I saw him he was cleaning his room. While he was waiting for the bus, he was reading a newspaper. He was cleaning his car while
