Whatever. Fine. I don't know.
Do those phrases just push every button you've got? It used to make me crazy when my (now 27-year old) son answered 'cool' to everything, including incredibly sad news. It took forever for me to understand that 'cool' just meant 'I heard what you said.'
To a parent, these expressions can feel confusing and confrontational. And, by the way, 'I don't know' generally means, 'I know, but I don't feel like talking about it.' 'Whatever' and 'fine' can mean that, too, as well as "I've had a hard day' or 'I'd rather be doing something else.' Don't take it personally, because it's rarely about you. They are speaking "teen", a foreign language with confusing meaning. (And I bet your parents were equally baffled by the jargon of your teen years, too.)
What expressions do your kids use that leave you scratching your head, or worse yet, yelling? They can mean anything from "You have no idea what my day was like" to "I'm confused" to "I'd rather be with my friends" to "I can't hear you when you lecture me".
If you're triggered by unfamiliar lingo, get a translator! Whether it's your child or another teen or young adult, it's in everyone's best interest for you to understand what the heck they mean! You know how a simple conversation can break down when you don't understand each other. Your kids may use familiar words in very different ways, and this increases the likelihood of a misunderstanding and decreases cooperation. As communications expert, Dr. Frank Luntz says, "It's not what you say, it's what people hear," and that works both ways with you and your kids.
Remember, too, that your mood and physical state will impact how you respond to your kids. If you're tired, overwhelmed or emotionally drained, you're going to have less patience. That goes double when their language triggers you, and things can get really messy. Communication stalls, relationships deteriorate and the brick wall goes up.
So have an open conversation with your teen. Explain how it really is confusing and you'd rather understand them than feel angry with them. Let them help you. They will feel needed and heard, and they'll appreciate the effort you're making to break through the language barrier.