Add ’s to form the possessive—or show ownership—of
a singular noun.
Add 's to form the possessive—or show
ownership—of a plural noun that does not end in s.
Add only the appostrophe to form the possessive
of a plural noun already ending in s.
Do not use an apostrophe with the pronouns his,
hers, its, ours, yours, theirs, whose, or with plural nouns that
are not possessive.