Apostrophe Use: Possessive Case Of Indefinite Pronouns

Indefinite pronouns can be made possessive with the use of ‘s. Indefinite pronouns are words like someone, other, and any.

It’s always good to know one’s enemy.

Is this anyone’s backpack lying here on the ground?

That’s not Helen’s handwriting; it must be someone else’s.

Try putting yourself in another’s shoes.