"What does the convenience store sell?"
Translation:편의점은 뭘 팔아?
@duolingo: same old freakgin inconsistency here: nothing specifies it HAS TO be informal so WHY is 팔아요 wrong? Can you explain somewhere on your (poorly made) website and notes? also you just randomly accept or reject formal/informal forms in general. 무엇을 and 뭘 are strictly the same but on different levels of formality. Either you accept all forms EVERYWHERE either you specify when you want people to use a specific form. Because right now you are just crazy inconsistent and missleading. Not to mention the amount of misstakes you do and teach people!!!!!! Get things right for god's sake