Almost every couple I work with already knows how to say "I'm sorry." Repair is a different skill, and it's the one that determines whether the same fight happens again next month.
Apology vs. repair
An apology closes a conversation. Repair reopens it — carefully, and on purpose — to understand what the fight was about underneath the thing you were fighting about.
Most arguments have a surface topic (dishes, money, a comment at dinner) and a real topic (feeling unseen, feeling criticized, feeling like you're carrying more than your partner). Repair means going back to the real topic once things have cooled down, not just moving on because the tension is gone.
A simple repair conversation
Try naming three things, separately: what you were feeling in the moment (not just angry — often something underneath the anger, like hurt or fear), what you think your partner was feeling, and what you each need going forward. This isn't about relitigating who was right.
Couples who never repair tend to build up a long list of unresolved moments instead of louder fights — and that list eventually shows up as distance instead of conflict. If repair conversations keep going sideways on your own, that's exactly what marriage counseling is for: someone in the room to keep both of you moving toward each other instead of further apart.