Casual Speech: 반말
Learn how to speak casually with friends using 반말 (informal speech).
반말 (casual speech, literally 'half-speech') is the intimate register used between close friends, family members of similar generation, and from older speakers to clearly younger ones in established relationships. The transformation is mechanical: drop the polite -요 from -아요/어요 endings. 어디 가요? becomes 어디 가? 좋아요 becomes 좋아.
The social dimension is critical: do not switch to 반말 with anyone you have just met, regardless of their apparent age. Native Korean speakers establish 반말 relationships through explicit social negotiation — typically the older or higher-status person initiates the switch by asking 우리 말 놓을까요? (shall we drop the polite form?). As a foreign speaker, you should almost always stay in 해요체 unless explicitly invited to use 반말. Using 반말 with a stranger can sound aggressive or childish; using 해요체 with a close friend who's invited 반말 can feel cold but is rarely seen as rude.
해요체 → 반말 Conversion
Simply drop 요 from 해요체. 먹어요 → 먹어, 가요 → 가, 했어요 → 했어, 좋아요 → 좋아. For ~ㄹ게요 → ~ㄹ게, ~ㄹ까요? → ~ㄹ까?
~자 — Let's (casual suggestion)
Verb stem + 자 = 'Let's ~' in casual speech. 가다 → 가자 (let's go), 먹다 → 먹자 (let's eat), 하다 → 하자 (let's do it). This is the 반말 equivalent of ~(으)ㄹ까요?