No. You can use the possessive markers for literally anything. "The cat's paw." "The table's leg." "The pencil's eraser." "The bread's water content." "The pigeon's beady eyes." and so on.

Mostly, yes. But not only, as Nikooru's answer demonstrates. There's no simple rule here. Depending on the situation, we can use: - the Saxon genitive ( 's ) - X of Y - adjective + noun - a compound noun (noun + noun) It's not possible to use any pattern, but you'll learn these rules as you go. Using 's for people is a good start.