Often times violence escalates gradually in a relationship.  Many victims describe their situation as starting out healthy and then it becomes very violent before they even realize it.  Here are some signs that you are in an unhealthy relationship.
Partner controls where the person goes or who they spend time with
Partner controls all aspects of the money
Partner puts the victim down emotionally by calling them names
Partner claims the victim made them behave this way
Partner might use looks or elevate voice to intimidate victim
Partner makes threats of homicide or suicide
Partner abuses a family pet
Partner destroys victims property
Partner forces victim to have sex with them
Partner uses the child as a pawn
Partner forces you to watch a movie that you feel is inappropriate
Partner has difficulty with authority figures such as police
Partner uses traditional gender roles such as the man should be the head of the household and in control
Partner doesn’t support you in your goals or hobbies
Partner physically abuses you and then apologizes saying it will never happen again