Shanli Liu, a CPA, shares a three-step method for setting boundaries in arguments: state what you won't accept ("I will not be yelled at"), name the consequence ("the conversation ends"), and actually follow through. The key is making it clear you mean it.
Chapters
How to assert boundaries in bad arguments. If an argument is getting heated and turning ugly to where the person is blatantly being disrespectful to you, you know, if you follow me, we do not walk on eggshells. We assertively put up boundaries. That means we start with number 1, I, I, and then insert your boundary. I will not be yelled at. I will not be spoken to that way. Notice how I didn't say you're not going to talk to me that way. I will not be spoken to that way. You're making it crystal clear that this This is my boundary. Number 2, add the consequence. It goes like this. If you continue to break boundary, this is the end of the conversation. For example, I will not be yelled at. And if you continue to yell at me, this is the end of the conversation. Full stop. Don't say another word. You've now put it on their side of the court to either respect your boundary or not. And number 3, you gotta mean it. You have to be prepared to hang up the phone or leave the room. You have to establish a precedent that you do exactly what you say you're gonna do, because if you don't, they will take advantage of you. So try that.