Possessive adjectives and pronouns are used to show that something or someone belongs to a person. The possessive adjective is used with a noun, the possessive pronoun is used without a noun.
The possessive pronoun replaces an possessive adjective + a noun:

This laptop is his laptop and not my laptop. This laptop is his and not mine.

Possessive Adjective Possessive Pronoun
This is my house. No, it's mine.
Is this your bike? No, it's yours.
This is his book. Yes, it's his.
Her pullover is green. No, hers is brown.
Here is its ball. ---- (We don't use its)
We like our dog. This dog is ours.
Is this your car? Yes, it's yours.
This is their telephone. No, it isn't theirs.


Adjectives Exercise 1 Exercise 2 Exercise 3 Exercise 4  
Pronouns Exercise 1 Exercise 2