음

Turns a verb into a noun

Makes a noun you can talk about out of a description or verb: dirtiness, cuteness, tastiness, boringness. It also ends a line as a bare noun instead of a full sentence — 'Landing feels promising', 'It's just not good, it's not fun' — a clipped style that reads like a label, which is why it fills captions and rating scales such as 'very good, good, normal, bad, very bad'. The noun-making use is completely standard; the clipped-ending use is casual written Korean and would sound odd spoken to someone.

Register: neutral as a noun; caption style as an ending