Answer:
I regularly change shape yet remain a sphere. I am always there but not often seen. What am I?
You buy me to eat, but never eat me. What am I?
My tail is long, my coat is brown. I like the country, I like the town. I can live in a house or live in a shed, and I come out to play when you are in bed. What am I?
As a stone inside a tree, I’ll help your words outlive thee. But if you push me as I stand, the more I move the less I am.
Though I am dark Adam married me.
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.