Not all apologies are created equal. While a good one can’t always fully undo the damage that’s been done, apologies help people on the receiving end feel validated, emotionally heal, and even ease a desire for revenge, says Seiji Takaku, a professor of psychology at Soka University of America in Aliso Viejo, Calif., who has researched forgiveness. If you’re on the receiving end of a sorry attempt to make amends, on the other hand, it might feel just as offensive as the original transgression.

How someone apologizes will determine how you respond. We asked experts what to say in a variety of situations—including when you want to accept the apology, when you definitely don’t, and when you simply need more time to forgive.