The most important thing you must do to demonstrate a sincere apology is to take the blame for your actions. Resist blaming your girlfriend in any way, such as by saying "I messed up was because you were getting too emotional." You are not apologizing for your girlfriend's feelings, but for your own behavior, according to Dr. Grohol. It is important to make this distinction when saying you're sorry.

Explain to your girlfriend that you are understanding of the situation you put her in. You should consider how your behavior affected her life, according to Beverly Engel in an article published by the University of Massachusetts at Amherst's Family Business Center. Maybe she has come to doubt your commitment to the relationship or wonder if you truly value her. Let her know that you understand the pain she is in and that you are sincerely sorry.

You may think that an apology is all about what you say, but listening to your girlfriend's perspective is actually an effective way to demonstrate regret. You must listen to the sentiments expressed by the offended party, according to Guy Winch, a licensed psychologist and author of "The Squeaky Wheel: Complaining the Right Way to Get Results, Improve Your Relationships and Enhance Self-Esteem." Your girlfriend may have something to tell you that is important to her. Listening patiently will show her that you truly value her perspective.

While you may not be able to take back the mistake you made, you can offer to try to make it up to your girlfriend. Perhaps she would enjoy a meaningful gift from you or a special date night. Only you know what would make her truly happy, so go out of your way to bring a smile to her face. You will show her that the two of you can overcome any challenge in your relationship, and that your mistake will not be the end of your devotion to her.