는데 (neun-de, neunde) · 더니 (deo-ni, deoni)
Both 는데 and 더니 connect clauses, but 는데 mainly provides background or contrast, while 더니 compares past experiences with current situations or links cause and effect.
One lane per word — no nested boxes, just the gist.
Connects clauses to provide background, contrast, or a smooth transition
When to use
background explanation, contrast expression, smooth transition
The nuance
Used mainly for describing current situations, contrast, or introducing new information; not suitable for comparing past experiences with current situations
Used to compare past experiences with current situations or to connect cause and effect
When to use
past-present comparison, cause and effect connection, emphasis on past experience
The nuance
Can only be used after mentioning past facts or experiences to contrast with the present or state a result
비가 많이 오는데 우산을 안 가져왔어요.
bi-ga man-i o-neun-de u-san-eul an ga-jyeo-wass-eo-yo., bi ga man i o neun de u san eul an ga jyeo wass eo yo.
Correct use of 는데 for describing current situation and background
비가 많이 오더니 길이 다 젖었어요.
bi-ga man-i o-deo-ni gil-i da jeoj-eoss-eo-yo., bi ga man i o deo ni gil i da jeoj eoss eo yo.
Correct use of 더니 to link past rain event with current wet roads
친구가 늦는데 기다렸어요.
chin-gu-ga neuj-neun-de gi-da-ryeoss-eo-yo., chin gu ga neuj neun de gi da ryeoss eo yo.
Correct use of 는데 to connect current situation and action
친구가 늦더니 피곤해 보여요.
chin-gu-ga neuj-deo-ni pi-gon-hae bo-yeo-yo., chin gu ga neuj deo ni pi gon hae bo yeo yo.
Incorrect because 더니 should connect past event with result; here, it describes current state without past reference
어제 운동을 많이 했는데 지금 몸이 아파요.
eo-je un-dong-eul man-i haess-neun-de ji-geum mom-i a-pa-yo., eo je un dong eul man i haess neun de ji geum mom i a pa yo.
Incorrect because cause-effect from past to present requires 더니, not 는데
어제 운동을 많이 했더니 지금 몸이 아파요.
eo-je un-dong-eul man-i haess-deo-ni ji-geum mom-i a-pa-yo., eo je un dong eul man i haess deo ni ji geum mom i a pa yo.
Correct use of 더니 to connect past action with present result
음악을 듣는데 기분이 좋아졌어요.
eum-ak-eul deut-neun-de gi-bun-i joh-a-jyeoss-eo-yo., eum ak eul deut neun de gi bun i joh a jyeoss eo yo.
Incorrect because linking past action and result requires 더니, not 는데
음악을 들었더니 기분이 좋아졌어요.
eum-ak-eul deul-eoss-deo-ni gi-bun-i joh-a-jyeoss-eo-yo., eum ak eul deul eoss deo ni gi bun i joh a jyeoss eo yo.
Correct use of 더니 for cause-effect from past action to present result
Which expression correctly connects past experience with present result?
Which expression is suitable for describing current situation and background?
What is the role of '더니' in the sentence 'I ate a lot yesterday, so my stomach hurts.'?
