Play is the work of a child, and every day is a learning experience. A child can whip up a science experiment using tools she finds at hand. Sure, to you it looks like she smeared an entire jar of Vaseline all over the couch, but what your child learned is that petroleum jelly is sticky and gooey, and it doesn’t come off of her fingers very easily, even if she wipes them on something like the couch. No, the rug isn’t much better at getting it off. Yes, the dog may lick some of it off, but he is not really interested. Sure, it still tastes the same after the dog licked it. Still doesn’t come off when you wipe it on the couch though.
Learning is a rapid, ongoing process for a child, not confined to the times of day that we set aside to teach. Use your child’s play to encourage their language growth and build vocabulary.