Answer:
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
A tangly game and a destructive weather phenomenon.
What has thousands of ribs and two backbones?
Which weighs more? A pound of iron or a pound of feathers?
What can speak without a tongue and listen without ears?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.