Which pronoun case type can function as an adjective?

The pronoun case type that can function as an adjective is the possessive case.

Here's why:

* Possessive pronouns show ownership or possession. They answer the question "Whose?"

* Examples: *my, your, his, her, its, our, their*

* Adjectives modify nouns or pronouns, providing more information about them.

Examples:

* My book is on the table. (*My* modifies *book*)

* Their car is red. (*Their* modifies *car*)

While other pronoun cases (nominative, objective) have their own grammatical functions, only the possessive case can directly function as an adjective.