Answer:
I work when I play and play when I work
I start in little but I end in full you'll find me in half and complete.
I'm sometimes white but most often I'm black. I take you there but never bring you back.
Can not be bought, Can not be sold, Even if it's made of gold. What is it?
I don't live within a house nor do I live without. Most will use me when they come in and again when they go out.
What language does a billboard speak?