(1)live为静态动词，动作不会结束，或者结束不可预料，没有进行体。
It happened while he was living in Beijing.（错误表达）
It happened while he lived in Beijing.(正确表达)
Tom lives in Beijing.(正确表达) Tom is living in Beijing.(错误表达）
备注：静态动词用于进行体通常表示“临时性的情况”。
(2)finish为瞬间动词，动作不具备持续性特点，所以没有进行体。
He was finishing his work at 6 yesterday.(错误表达)
He finished his work at 6 yesterday.(正确表达)
备注：瞬间动词进行体通常表示“动作重复发生或者将要发生动作”。
