In English, the pronoun case type that can function as an adjective is the possessive pronoun. Examples of possessive pronouns include ‘my’, ‘your’, ‘his’, ‘her’, ‘its’, ‘our’, and ‘their’. These pronouns indicate ownership or a relationship to a noun.
For instance, in the phrase ‘my book’, the word ‘my’ modifies the noun ‘book’, showing that the book belongs to the speaker. This use of possessive pronouns effectively allows them to take on an adjectival role, providing more information about the noun they accompany.