My daughter just turned 3 years old, and has been able to talk very clearly since she was about 10 months. But, recently she has come up with a sort of 'play' language. I'm not sure if she is secretly conversing with the house elves or what, but it is quite amuzing and bewildering.... When I hear her speak a word from her own language, I'll ask her what it means and her answer is always a very complicate one. Here's an example of one of her words.
"Trafelgotin" she says.
"What's a 'trafelgotin', Jane?" ask I.
And she replies "Its a dog that flies like a bee with butterfly wings and he licks my nose and sits in my hand."