Answer:
I can be swallowed, but I can also swallow you. What am I?
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?
I am a rock group with four members all of whom died in plane crashes. Who am I?
I regularly change shape yet remain a sphere. I am always there but not often seen. What am I?
My rings are not worth much, but they do tell my age. What am I?
It rows quickly with four oars but never comes out from under his own roof. What is it?