반말 (banmal) — casual/informal speech. 존댓말 (jondaetmal) — polite/formal speech.

If you’ve mastered the basics of polite vs. casual Korean, you know that dropping the “yo” (-요) at the end of a sentence changes the whole vibe. In K-dramas, the moment a character switches from jondaetmal (polite speech) to banmal (casual speech) is a major plot device used for romantic milestones, accidental slip-ups, and fierce power moves.