Warning signs for someone else:
Visibly controlling
Constantly checking on their partner in an eerie way
Change (negative) in personality
Cruelty to animals or children
Warning signs for you:
Being overly critical
Accessing private accounts such as goo gle, tw itter, etc and has to know your passwords
Never being at fault
Saying you did things they did
Extreme jealousy
And of course, physically hurting you