Pronouns showing ownership do not use an apostrophe.
his, hers, ours, theirs, yours, its
These pronouns all show possession or ownership. All end in an s. However, we don not use an apostrophe with these possessive words.
The dog is hers.
The bike is yours.
The house is theirs.
The book is ours.
Do not use an apostrophe in possessive pronouns.
It’s your turn. Put a possessive pronoun into this sentence. The squirrel ran into ____ nest. Did you figure it out? Good for you!