Halfway through a fight, ask “What are we actually arguing about?” Sometimes nobody knows anymore.

Arguments drift. The subject changes three or four times while the heat stays constant, so you end up defending positions with no connection to where it started and no memory of how you arrived. The question interrupts the momentum without anybody having to lose, since neither of you has to concede in order to answer it. Quite often the real answer is small and surprises both of you.

Use it out loud the next time one is going sideways, and let them answer first. If neither of you can name the topic, agree to stop. If you can, deal with that and leave the rest.