Here are some key points about interrogative adjectives:

1. Definition: Interrogative adjectives are used to modify nouns and introduce questions, helping to inquire about specific information related to the noun.

2. Types: There are two main interrogative adjectives in English: "which" and "what."

3. "Which": "Which" is used when there is a limited or specific set of options or choices. It asks for a selection or preference among alternatives.

   • Example: "Which book did you choose?" (Asking about a specific book from a set of options)
     • "Which movie did you watch last night?"
     • "Which color do you prefer, red or blue?"
     • "Which book belongs to you?"

4. "What": "What" is used when there is an open-ended or general inquiry, asking for information or description.

   • Example: "What color is your car?" (Asking for the car's color without specifying options)
     • "What time is the party?"
     • "What type of music do you like?"
     • "What is your favorite food?"

5. Placement: Interrogative adjectives are placed before the noun they modify.

   • Example:
     • "Which shirt are you wearing?"
     • "What book are you reading?"

6. Use in Questions: Interrogative adjectives are commonly used to form questions that seek information about the noun.

   • Example:
     • "Which restaurant serves the best pizza?"
     • "What time is the meeting?"

7. Agreement: Interrogative adjectives do not change in form based on the number or gender of the noun they modify.

8. Use with Nouns: Interrogative adjectives are used directly before a noun to ask a question about that noun.

   • Example:
     • "Which car do you want to buy?" (Asking about a specific car)

Interrogative adjectives help to gather specific information or seek clarification by modifying nouns and forming questions. By using them appropriately, you can inquire about details, preferences, or characteristics related to the noun in question.