couldst，英语单词，主要用作
动词，作动词时译为“能够（can 的过去式）”。
单词用法
柯林斯英汉双解大词典
couldst /kʊdst/
1.V[archaic] → used with the pronoun or its relative form, the form of could
双语例句
How couldst thou come quicker than I?你怎么能比我来得快呢？
How couldst thou forget thine own faults and busy thyself with the faults of others?你怎么可以忘记自己的错误而忙于挑剔别人的过失呢?。
If only thou couldst see when the guilty ones will bend low their heads before their Lord, Our Lord!假若你得见犯罪者在他们的主那里垂头丧气地说：我们的主啊！