What are the differences among "What/Which/Why/When" in English? This test was designed for you to practice "What/Which/Why/When". The test has 20 questions. Before taking the test, please read the following tips about "What/Which/Why/When".

- 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.