The possessive case and pronouns

A word used in the possessive case shows ownership. Possessive pronouns do not require
apostrophes.

The singular possessive pronouns aremy, mine, your, yours, his, her, hers, and its.
The plural possessive pronouns are our, ours, your, yours, their, and theirs.
The possessive pronoun whose also does not require an apostrophe.
This house is theirs.
Their car is currently in the shop.
Your notebook and my textbook are in the school’s cafeteria.
Is that package theirs or ours?
The movie has lost its appeal with her children.
His bike is locked up next to mine in your space.

Note: Though a noun that precedes a gerund (word that ends in -ing and functions as a
noun) requires an apostrophe, the pronoun that does the same does not require one.
Nina’s selecting that prize was very interesting. (Nina’s, a possessive noun/adjective,
requires an apostrophe.)
Her selecting that prize was very interesting. (Her, a possessive pronoun/adjective, does
not require an apostrophe.)