Apostrophe And Possessive Pronouns

Possessive pronouns don’t require an apostrophe.

Who’s book is that? = Whose book is that?

That book is his’. = That book is his.

No, it’s mine’s! = No, it’s mine!

The cat washed it’s face. = The cat washed its face.

N.B. It’s is a contraction of it is, not a possessive pronoun.

Exception:

Indefinite pronouns can be made plural.

One – one’s

It is best to mind one’s own business.

One should always look one’s best.