They will keep telling you I LOVE YOU SO MUCH but their attitudes shows they don't really feel anything for you.
Such people need to be avoided or they will hurt you when you never expected them to hurt you.
They don't care about you, no remorse of change in them, they keep telling you,I WILL CHANGE but no improvement.
Caring and being there for your partner is important in a relationship. 
He/she is always selfish, if you find out your partner is selfish,its a very big disease.
When your partner normally beats you up or keep
abusing you. Constantly making you angry,its a big sign you're in a wrong relationship. Nobody is perfect but constantly repeating offenses is bad. 
Infidelity is the most annoying part of it. If your partner truly love you, he/she will not be cheating on you. When your lover keep cheating on you. You are in a wrong Relationship. There's big possibilities he or she will continue cheating in marriage. Don't over look cheating in your courtship.<
A wrong partner will never care and appreciate what
you're doing for him/her. They suck ,boring and forming rubbish, their attitude and ways of life are irritating.
A wrong partner who may frustrate you in future, find it hard to say> I'm Sorry> Forgive me. Wrong lovers don't apologies to their partner.
can't change anyone
True, a relationship is to be enjoyed not endured, and everything works both ways.