Cách sử dụng
The expression "flog a dead horse" means to continue to do something that is not going to work, even though you know it is not going to work. It's like hitting a horse that is already dead - it's pointless and won't achieve anything. You can use this expression to say that someone is wasting their time trying to do something that will never work or achieve anything. For example, "I know you want to convince your boss to give you a raise, but you keep asking him every week. You're flogging a dead horse - it's not going to work."