Grammar - possessive pronouns

study ex 1 ex 2
 
1. Form and example
They do not change according to the thing possessed, but according to the possessor
 
mine
yours
his
hers
-
ours
yours
theirs
This is my chair. It's mine
These are your books. They are yours.
Is this his dog? Is it his?
Where are her toys? Where are hers?

These are our jackets. These are ours.
These are our books. These are yours
Where are their plants? Where are theirs?
 
There is no possessive pronoun for 'it'. We use 'its own' instead:
Your dog is eating my dog's bone, why can't it eat its own?