Answer:
I am in the middle of water but am not an island.
I'm tall when I'm young and I'm short when I'm old. What am I?
My first half means container. Not a lot of people understand my language.
I can be written, I can be spoken, I can be exposed, I can be broken. What am I?
I climb higher as I get hotter. I can never escape from my crystal cage.
Runs over fields and woods all day. Under the bed at night sits not alone, With long tongue hanging out, Resting at your feet until we go for a walk