Nope. It's play-acting. They are learning the question/answer role. You can tell this by the simple fact that a rampaging 3 year old is not listening to the answers.
Don't get me wrong, I'm in the unschooling/homeschooling camp, but this isn't evidence of enthusiasm. :)
Do they listen to anything other than accidental F bombs?
It's tough when they're 4. They can read a little, but too young for Google. And I'm afraid of some of the unfiltered answers. :-)