Chinese translation for: Beating a dead horse Anyone know the Chinese 成语 equivalent for 'Beating a dead horse'? Beating a dead horse: This is when someone is trying to convince people to do or feel something without any chance of succeeding. This is also used when someone is trying to raise interest in an issue that no-one supports anymore. I have heard the following suggestions, but I am not sure which (if any) is the best equivalent： 白费功夫 老生常谈 死马当作活马医：But 死马当作活马医 is more 正面。And beating a dead horse is definitely 负面的。)