What is a possessive noun?

A possessive noun is a noun like “farmer’s” that is used to indicate ownership (possession). It normally comes before another noun that indicates the thing possessed (e.g., “the farmer’s pitchfork”).

Possessive nouns are formed from regular nouns by adding an apostrophe followed by an “s,” or, in the case of plural nouns that already end in “s,” by just adding an apostrophe.