- What: Used to ask for information, the thing
Ex: What are you doing?
- Which: Talk about a thing in things, or a person in a group
Ex: Which one do you want? Red car or blue car?
- Why: Ask reasons for something you use why
Ex: Why are you late?
- When: Ask about time, at what time
Ex: When will you come here?
Now You'll take a "What/Which/Why/When" test.