Possessive pronouns refer to something which belongs to someone or something. They can take the place of both the pronoun and the noun which is possessed, and they’re generally found at the end of the clause or sentence. The possessive pronouns are mine, yours, his, hers, ours, yours, theirs and whose.
The green shirt is mine; the red one is his.
The first clause mentions the subject (the green shirt), and the possessive pronoun mine makes it clear that the speaker owns the shirt; the second clause uses the pronoun one to replace shirt, and the pronoun his to show the red shirt belongs to some man who has been previously mentioned (or otherwise clarified: the speaker could be pointing to him).
The green shirt is mine; the red is his.
This sentence is a little more informal, but it’s still perfectly clear.
After the hurricane, the survivors rescued whatever was theirs.
That house is ours.
Whose pen is this?
Possessive determiners replace just the person who owns the item. They must always be followed by a noun. The possessive determiners are my, your, his, her, its, our, your, and their.
My house or yours?
My is the possessive determiner, which is followed by the noun house.
The woman fluffed up her hair.
The bird added a small stick to its nest.
Where did your brother get to now?
Did they get their tax-return yet?