Answer:
What has two spines and a lot of ribs, and carries much but never moves?
You use a knife to slice my head. And weep beside me when I am dead.
There are two meanings to me. With one I may need to be broken, with the other I hold on. My favorite characteristic is my charming dimple.
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
My tongue hangs out as I run over fields and streets all day. I get tied up every morning and untied at night.
I repeat only the last word you say. The more I repeat, the softer I got. I cannot be seen but can be heard. What am I?