What is an interrogative adjective?

Interrogative adjectives (also called interrogative determiners) are words that modify a noun or pronoun to form a question (e.g., “Which shirt do you like?”). The three interrogative adjectives are “which,” “what,” and “whose.”

Interrogative adjectives belong to a larger class of words, sometimes referred to as “interrogatives.” When “which,” “what,” and “whose” are used to stand in for a noun, rather than modifying it (e.g., “Which do you like?”), they are known as interrogative pronouns.