You know when you're lecturing. You can see it on your child's face. Or in the eye-rolling. Or in the sigh. But you keep going because now they're being disrespectful and you're going to make your point if it's the last thing you do! He knew what was coming in the first minute, well actually in the first sentence, and he's not interested in hearing any more.
You've lost this round, in more ways than one. You're frustrated and they've mentally checked out. Whatever lesson you're trying to teach is now out the window. Nagging doesn't teach responsibility... it teaches your child to tune you out and avoid all the things you want him to do, or not do.
With teens, and most people, less is more. Say it in a word or two. Your laundry. Be home by 11:00. No phones at the table. Message delivered. Time to move on.
Here are more resources on how to improve communication with your teen:
The Ticket or the Lecture? http://bit.ly/gSaedD
American Psychological Association