“怀恨”常见的英文表达是 “bear a grudge (against someone)” 或 “hold a grudge (against someone)”，这两个短语都强调长期心怀怨恨、不满的情绪。
She still bears a grudge against her ex-husband for what he did. （她仍因前夫所做的事而对他怀恨在心。）
He has been holding a grudge against his former colleague ever since that argument. （自那次争吵后，他就一直对前同事怀恨在心。）
此外，也可以用 “resent (someone/something)” 来表达“怀恨；怨恨”的意思，不过它更侧重于表达内心的不满和愤怒情绪，不一定强调长期性。
She resents her boss for always giving her the most difficult tasks. （她怨恨老板总是把最困难的任务派给她。）