This document examines the differences between possessive pronouns and possessive determiners. Possessive pronouns replace nouns that indicate ownership and function as subjects or objects in sentences, such as "mine", "yours", and "theirs". Possessive determiners specify the object being owned as modifiers and cannot be mistaken for something else, such as "my", "your", and "their". Examples are provided to illustrate how possessive pronouns replace nouns while possessive determiners modify nouns. The document concludes by explaining the differences and providing a link to an explanatory video.