Answer by Thomas Zerbarini:
When the willingness to be patient, tolerant and respectful of each other wanes. If you have little or no interest in making a relationship work, it will find it's way to failure.
If you think you're done and say you are done, you're probably done.
If you are not sure and still want to work it out and seek resolution to your differences, then you're probably not done. Only you will know if you're not willing to continue in a relationship.
Of course it takes two to be willing and committed to a relationship. If the other is not, you're done!
I have been in relationships when the other partner has abandoned that willingness and commitment to the relationship. There is nothing you can do about the other person except express your true feelings and concerns and eventually move on.