TOPIK II Grammar · Ch.4 Time, Experience & Recollection 03

TOPIK II Grammar · Ch.4 Time, Experience & Recollection 03

'-더니' vs '-았/었더니' - A Change I Watched, a Result I Found

동생이 열심히 공부하더니 장학금을 받았어요 - I watched my brother study hard, and then he got a scholarship. 약을 먹었더니 금방 나았어요 - I took the medicine, and I got better quickly. English has no single form for this; it needs a whole extra clause like "I noticed that...". Korean packs the watching into one ending - and who the subject is decides everything.

Key point -더니 = a change or result I observed in someone (or something) else. -았/었더니 = the result I found after doing something myself. First-clause subject: someone else → -더니; me → -았/었더니.

How to use it

The closest English to -더니 is a sentence pair: "I saw X happening - and then Y." The ending carries both the eyewitness memory and the sequel: 아침에는 흐리더니 오후에 갰어요 (= it was cloudy in the morning - I saw it myself - and cleared up in the afternoon), 그렇게 울더니 지금은 웃네요 (= after all that crying, now she's smiling). What follows is a change or a contrast in the thing you watched.

-았/었더니 reports on something you tried yourself: I did A, and here's what I found. 창문을 열었더니 시원한 바람이 들어왔어요 (= I opened the window, and a cool breeze came in). 오래 걸었더니 다리가 아파요 (= I've walked a long time, and my legs hurt).

So the sorting rule is one question: who is the subject of the first clause? Someone or something else → -더니. Me → -았/었더니. One ending watches from outside; the other reports from inside.

At a glance

Pattern	First-clause subject	Example
-더니 (change)	someone else · the outside world	매일 운동하더니 건강해졌어요
-더니 (contrast)	weather · situations	어제는 춥더니 오늘은 따뜻하네요
-았/었더니	me	일찍 잤더니 몸이 가벼워요

What follows  Both endings lead to a result or discovery. Commands and suggestions (-(으)세요, -(으)ㅂ시다) don't follow them - the second clause states what happened; it doesn't ask for anything.

Examples

친구가 한국 드라마를 많이 보더니 발음이 좋아졌어요. My friend watched a lot of Korean dramas, and her pronunciation improved. - a change I observed in someone else.

음악을 들었더니 기분이 좋아졌어요. I listened to some music, and it lifted my mood. - my own action, my own result; 듣다 becomes 들었- as usual.

오전에는 사람이 없더니 지금은 아주 많네요. There was no one here this morning, but now it's crowded. - a contrast between two situations I saw myself.

Common mistakes

❌ 제가 열심히 연습하더니 대회에서 상을 받았어요. → ⭕ 제가 열심히 연습했더니 대회에서 상을 받았어요. Your own action and its result take -았/었더니. With -더니 the sentence sounds like you watched yourself from across the room - the observer's ending doesn't fit the doer.

❌ 동생이 약을 먹었더니 나았어요. → ⭕ 동생이 약을 먹더니 나았어요. The one who took the medicine is your younger brother, and you watched the change happen - that's the place for -더니. -았/었더니 is reserved for reporting your own experience.

Quick check

Fill each blank with -더니 or -았/었더니.

1. 하늘이 어둡(      ) 결국 비가 오네요.
2. 매운 것을 먹(      ) 배가 아파요. (my own experience)
3. 언니가 매일 단어를 외우(      ) 시험에 합격했어요.

Show answers

1. 더니 (the subject is the sky, not me - an observed change)   2. 었더니 (먹었더니 - I did it, and I felt the result)   3. 더니 (the subject is my sister, someone I watched)

💡 Study tip - Write a two-line diary. One line about someone else - 친구가 ~더니 ~ - and one about yourself - ~았더니 ~. And on the exam, circle the subject of the first clause before anything else: for this pair, the subject alone decides the answer.