"What?"

Translation: 무엇?

[LiKenun]

The forms of 무엇:

• 뭣

• 뭐

• 뭔←무엇은

• 뭘←무엇을

[Swauger]

So in what context do we use these forms?

[Bat_is_bat]

I think for the last two it's defined by the particle : object or subject. Can't tell for the others.

[Eien19]

All of these forms are now using?

[CooperReid4]

Frist two at just shortened forms. Third one is with the subject particle and has the shortened too. Forth one is with the object particle and also has the shortened form