Was
“Was” 对应现在时的 “am/is”，用来描述过去某一时刻的情况。它可作系动词，也可作助动词，与现在分词构成过去进行时，或与过去分词构成被动语态的过去表达。
- “He was tired after the long flight.” (长途飞行后他很累。)
- “The store was closed when we arrived.” (我们到时商店已经关门了。)
- “She was writing a report all afternoon.” (她整个下午都在写报告。)
“Was” 源自古英语 “wæs”，与德语 “war” 等同源，属于印欧语系中表示“存在、是”的不规则变化形式。
“Was” 是不可拆分的不规则过去式，没有可分析的生产性词缀。
叙事、新闻、回忆录里 “was” 极高频；口语中常与 “just”、“already” 等副词搭配说明时间先后。
- 固定搭配: “was born” (出生于), “it was said that” (据说), “was able to” (过去能够)
把 “was” 想成 “is” 的“往事版”：同一画面往回拨到过去，就用 was。
“The concert was wonderful, and the crowd was cheering for an encore.” (音乐会精彩极了，观众欢呼着要返场。)