A real apology has no “but” in it. That’s what makes it scary.

An apology stops working at the word but, because everything after it is a defense lawyer arriving. The plain version leaves you nothing to hide behind, which is exactly why it is frightening and exactly why it repairs anything. People hear the difference immediately, even when they could not name it.

If you owe one, write it out and delete every explanation you find. Name what you did, say you are sorry, say what you will do differently. Then stop, and let the other person have whatever reaction they have.