Testing limits is a normal part of your teen's development, according to childhood development expert James Lehman, MSW in an article published on Empowering Parents. At some point, she may start crossing the line between limit-testing and disrespect. Using curse words, calling you names and open defiance of rules are examples of disrespectful behaviors. The key to stopping disrespectful behavior is to use accountability and appropriate consequences.
Avoid taking it as a personal attack. It may be difficult to believe those angry words and actions aren't meant for you personally, but they aren't. Teenagers lash out at people they feel closest to, because it is from those people they are seeking their independence as they navigate their way between childhood and adulthood. The disrespectful behaviors may be directed at you but aren't really about you at all.
Keep house rules clear and few. Your teenager needs to know exactly what behaviors will not be tolerated. For example, if he is expected to follow a curfew, refrain from using illegal substances and maintain a 3.5 GPA at school, sit down and explain these rules to him. Also outline what the consequences will be if he chooses to break the rules. If he breaks the rules, there will be no need for an argument or disrespectful behavior because the consequence was discussed beforehand. Disrespect can happen in an escalated attempt to get you to change your mind about a consequence. Don't give in and he will see it doesn't work.
Show him how to treat people with respect. Your teen watches your actions more than he listens to your words. Displaying behaviors that demonstrate respect for others teaches him how to handle himself. For example, if your neighbor accidentally mows down your favorite rose bush, instead of yelling, insulting or being otherwise disrespectful about the situation, discuss it calmly and suggest a remedy. Treat your teenager with respect as well. Even when he loses his cool, do not respond in kind. Show him by your own actions how to make your point without using disrespect.
Encourage discussions. Depression, anxiety and stress can cause your teen to become disrespectful, so sit down with him and ask him if something is bothering him. If he tells you about a problem he has, help him explore solutions. Remind him later that disrespect will still not be tolerated, but you understand now where it was coming from and hope he will come to you when he has a problem in the future.