“一蹶不振”常见的英文表达有 “never recover from a setback”、“be unable to bounce back” 或者 “go to pieces after a single blow”。
“never recover from a setback”：强调在遭受挫折后，无法再恢复到之前的状态或水平，突出“振作不起来”这一结果。例如：After losing that important contract, the company never recovered from the setback.（在失去那份重要合同后，公司一蹶不振。 ）
“be unable to bounce back”： “bounce back”有“恢复；反弹”之意，该短语表示没有能力重新振作起来。例如：He was so devastated by the failure that he was unable to bounce back.（这次失败让他深受打击，一蹶不振。 ）
“go to pieces after a single blow”： “go to pieces”意思是“崩溃；垮掉” ，“after a single blow”表示“遭受一次打击后”，整体表达在经历一次挫折后就彻底垮掉。例如：The team went to pieces after a single blow in the championship game.（在冠军赛中遭受一次打击后，这支队伍就一蹶不振了。 ）