Parents can look for some early warning signs of abuse that can help you identify if your teen is in an abusive relationship before it's too late.  Some of these signs include:

• your teen's partner behaves in a way that is exremely jealous or possessive, such as checking in on your daughter or son often
• you hear verbal abuse, such as name-calling and demeaning comments
• your teen gives up things that are important, such as time with friends and family, activities, or other interests
• your teen has unexplained injuries

Other signs also include

More common clues that indicate a teenager may be experiencing dating violence:

What can you do?

• Tell your teen that you are concerned for his or her safety. Point out that what is happening is not 'normal'. Everyone deserves a safe and healthy relationship. Offer to connect your teen with a professional, like a counselor or attorney, who they can talk to confidentially.
• Be supportive and understanding. Stress you are on their side. Provide information and non-judgemental support.  Let them know that the abuse is not their fault, and that no one 'deserves' to be abused.  Make it clear that you don't blame your teen and that you respect his or her choices.
• Develop a safety plan. One of the most dangerous times in an abusive relationship can be when the victim decides to leave. Be especially supportive during this time and try to connect your teen to support groups or professionals that can help keep them safe.
• Remember that ultimately your teen must be the one to make the choice to leave the relationship. There are many complex reasons why victims stay with their abuser. Your support can make a critical difference in helping your teen find his or her own way to escape the abuse and become safe.

(sources:  Break the Cycle, teendvmonth.org, Delaware Coalition Against Domestic Violence)