-더니
I Noticed, And Then
-더니 connects two clauses, where the first clause is something the speaker observed in the past, and the second clause is the result or a contrasting situation that followed.
How It Works
-더니 is a versatile connective ending that links a speaker's past observation to a subsequent event. It carries the nuance of "I saw/noticed that [clause 1], and then/but now [clause 2]." Understanding its two primary uses is key.
1. Cause and Effect / Sequential Action
This usage connects an observed action/state with its direct result. The key rule here is that the subject of the first clause is usually a third person (he, she, they) or an inanimate object, not the speaker.
- 동생이 매일 운동하더니 건강해졌어요. (My younger sibling exercised every day, and as a result, they became healthy.)
- 바람이 세게 불더니 나뭇가지가 부러졌어요. (The wind blew strongly, and then a branch broke.)
In these cases, the speaker is reporting an observation and its outcome.
2. Contrast or Change Over Time
This usage highlights a difference between a past observation and the present situation. The subject can be anyone (first, second, or third person).
- 어제는 날씨가 춥더니 오늘은 따뜻하네요. (Yesterday the weather was cold, but today it's warm.)
- 그 배우가 예전에는 인기가 없더니 지금은 스타가 되었어요. (That actor used to be unpopular, but now they've become a star.)
When the subject is the speaker ('I'), it typically describes a state of being, not a deliberate action. For actions performed by the speaker, -았/었더니 is used.
- 아까는 머리가 아프더니 지금은 괜찮아요. (I had a headache earlier, but now I'm fine.)
Important Distinction: -더니 vs. -았/었더니
This is a common point of confusion for learners.
- -더니: Used when observing someone/something else's action or a change in state. The subject is usually not 'I' when describing an action.
- -았/었더니: Used when the speaker ('I') performs an action and then discovers or experiences a result.
Compare:
- 친구가 열심히 공부하더니 시험에 합격했어요. (My friend studied hard, and then they passed the test. - Observation of another person)
- 내가 열심히 공부했더니 시험에 합격했어요. (I studied hard, and (I found that) I passed the test. - Speaker's own action and discovery)
Examples (4)
- 동생이 아침부터 게임을 하더니 결국 엄마한테 혼났어요.
My little brother played games since the morning, and as a result, he eventually got scolded by Mom.
Word by Word: Younger sibling from morning games played and then in the end to mom got scolded.
The speaker observed the brother playing games (cause), which led to the result of being scolded.
- 어제는 날씨가 흐리더니 오늘은 해가 쨍쨍하네요.
Yesterday the weather was cloudy, but today the sun is shining brightly.
Word by Word: Yesterday weather was cloudy but today sun is shining brightly.
This shows a contrast between the observed state yesterday and the current state today.
- 그 아이가 어릴 때는 말을 잘 안 하더니 지금은 아주 수다스러워요.
That child didn't talk much when they were young, but now they are very talkative.
Word by Word: That child when young words well not speak but now very is talkative.
This contrasts a past observed characteristic with the present one.
- 친구가 계속 기침을 하더니 감기에 걸린 것 같아요.
My friend kept coughing, and now it seems like they've caught a cold.
Word by Word: Friend continuously coughed and then a cold caught seems like.
The observation of coughing leads to the speaker's conclusion that the friend has a cold.
Common Mistakes
Using -더니 with a first-person subject ('I') for an action that the speaker performed.
Not Quite내가 도서관에 가더니 친구를 만났어요.Better내가 도서관에 갔더니 친구를 만났어요.When the speaker performs an action (like going to the library) and then discovers or experiences a result (meeting a friend), you must use -았/었더니. -더니 is used when you observe someone else's action or a change in state.
Learn This First
To express 'I noticed and then', you need past observation markers and conjugation.
Related Patterns
- -았/었더니When I Did, After Doing
This is a crucial pattern to compare. While -더니 is for observing a third person's action or a change in state, -았/었더니 is used when the speaker (first person) performs an action and then discovers a result.
- -더-Past Observation Marker
-더- is the core retrospective marker within -더니. Understanding that -더- signifies the speaker's past observation or experience helps clarify the meaning of -더니.
- -ㄴ/는데Background Info, But
-ㄴ/는데 also connects clauses by providing background information. However, -더니 implies a stronger, more direct link of cause-and-effect or sharp contrast based on personal observation, while -ㄴ/는데 is more general.
- -(으)니까So, Because
Both can express a reason. -니까 states a logical or subjective reason. -더니 indicates a reason that is based on the speaker's direct observation of an event that led to a specific outcome.