Is cussing in private a sin?

I’ve said a couple of four letter words in private, half letting myself say what I knew was wrong and half out of habit. For the most part, I was aware that what I was doing was a sin, so are these mortal sins? I took the Eucharist today and I’m concerned that I need to go to confession.
Thank you for your help!

The following link should answer your question about swearing. If you have any further questions, please contact Catholic Answers directly.

Recommended Reading:

Is profanity a mortal sin?

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit