Question words are a super important part of any language.
Do you know all your Korean ones?! Which do you think is the hardest for you to remember?
Who? - 누구 (nu-gu)
What? - 뭐 (mweo)
When? - LEAVE THE ANSWER IN THE COMMENTS
Where? - 어디 (eo-di)
Why? - 왜 (wae)
How? - 어떻게? (eo-ddeo-ke)