What is a possessive noun?

A possessive noun is a type of noun that indicates ownership or a relationship between two nouns. This is typically formed by adding an apostrophe and the letter "s" to a noun, such as in "the dog's leash," where "dog" is the possessive noun indicating that the leash belongs to the dog. The concept of ownership is crucial to understanding possessive nouns, as they are specifically used to clarify to whom something belongs.

In contrast, the other options focus on different functions. A noun that shows an action corresponds to verbs, while a noun that shows location typically refers to places or positions, which would involve nouns defining where something is. Lastly, a noun that describes emotion relates to feelings or states of being associated with nouns but does not indicate possession. Therefore, possessive nouns are exclusively linked to the idea of ownership, making the correct option that which defines this concept.