-ㄴ/는/ㄹ 줄 알았다
I Thought That…, I Assumed That…
Used to say 'I thought...' or 'I assumed...', often implying the assumption was wrong. It can also mean 'I knew that...' when something happens as expected.
How It Works
This pattern, -ㄴ/는/ㄹ 줄 알았다, is versatile and its meaning heavily depends on the context and tone. Let's break down its two primary uses and conjugation rules.
1. Mistaken Assumption (Most Common)
This is used when you believed something to be true, but later found out it was not. It carries the nuance of 'I thought..., but I was wrong.'
- 저는 그가 의사인 줄 알았어요. (I thought he was a doctor, but he isn't.)
- 오늘이 토요일인 줄 알았어요. (I thought today was Saturday, but it's not.)
2. Knew It All Along / As Expected
This is used when an event unfolds exactly as you predicted. It can be used positively or negatively.
- 네가 시험에 합격할 줄 알았어! (I knew you would pass the test!) - Positive
- 그럴 줄 알았어. 또 지각이네. (I knew it. You're late again.) - Negative
Conjugation Rules:
A. Adjectives & 이다 (to be)
- Vowel stem + -ㄴ 줄 알았다: 예쁘다 → 예쁜 줄 알았다 (I thought she was pretty)
- Consonant stem + -은 줄 알았다: 좋다 → 좋은 줄 알았다 (I thought it was good)
- Nouns + -인 줄 알았다: 학생이다 → 학생인 줄 알았다 (I thought he was a student)
B. Action Verbs
- Present Tense: Stem + -는 줄 알았다
가다 → 가는 줄 알았다 (I thought he was going) - Past Tense: Stem + -ㄴ/은 줄 알았다
This form indicates an assumption about a completed action.
- Vowel stem + -ㄴ 줄 알았다: 오다 → 온 줄 알았다 (I thought he had come)
- Consonant stem + -은 줄 알았다: 먹다 → 먹은 줄 알았다 (I thought he had eaten)
C. Future / Supposition (Verbs & Adjectives)
- Vowel stem + -ㄹ 줄 알았다: 오다 → 올 줄 알았다 (I knew he would come)
- Consonant stem + -을 줄 알았다: 먹다 → 먹을 줄 알았다 (I knew he would eat)
This future/supposition form is most often used for the 'I knew it all along' meaning.
Examples (5)
- 저는 그 사람이 한국 사람인 줄 알았어요.
I thought that person was Korean.
Word by Word: I that person Korean person was I thought.
This implies that the speaker discovered the person is not Korean. This is the 'mistaken assumption' usage with a noun + 이다.
- 비가 오는 줄 알았는데, 날씨가 맑네요.
I thought it was raining, but the weather is clear.
Word by Word: Rain is coming I thought, weather is clear.
Here, the speaker's assumption about the present situation (it's raining) was incorrect. Uses the present tense verb form
-는 줄 알았다. - 친구가 벌써 집에 간 줄 알았어요.
I thought my friend had already gone home.
Word by Word: Friend already to home went I thought.
The speaker assumed a past action (the friend going home) had already happened, but it seems they are still here. Uses the past tense verb form
-ㄴ 줄 알았다. - 네가 이길 줄 알았어! 정말 축하해!
I knew you would win! Congratulations!
Word by Word: You would win I knew! Really congratulations!
This is an example of the 'I knew it all along' meaning, used in a positive and encouraging way. It uses the future/supposition form
-ㄹ 줄 알았다. - 그럴 줄 알았어. 결국 또 싸우는구나.
I knew it. You two ended up fighting again.
Word by Word: That would be so I knew. In the end again are fighting.
This shows the negative/resigned usage of 'I knew it all along'. The speaker predicted a negative outcome, and it happened.
Common Mistakes
Using the present tense form for a past event.
Different Meaning어제 영화가 시작하는 줄 알았어요.Better어제 영화가 시작한 줄 알았어요.When you thought a past action was completed, you must use the past tense modifier.
시작하는 줄 알았다means 'I thought it is starting,' which is awkward with 'yesterday'.시작한 줄 알았다correctly means 'I thought it had started.'Confusing it with
-ㄹ 줄 알다(to know how to do something).Different Meaning저는 어렸을 때 피아노를 칠 줄 알았어요. (This can be ambiguous)Better저는 어렸을 때 피아노를 칠 수 있었어요. (To clearly state ability in the past)피아노를 칠 줄 알았어요could mean 'I thought I would play the piano (but I didn't)' or 'I knew how to play the piano'. To avoid ambiguity when talking about a past ability, it's often clearer to use-ㄹ 수 있었다. The pattern-ㄴ/는/ㄹ 줄 알았다is primarily for assumptions, not abilities.
Learn This First
To express past incorrect assumptions, you need knowledge patterns and past tense.
Related Patterns
- -ㄴ/는/ㄹ 줄 몰랐다I Didn’t Know That…, I Had No Idea That…
This is the direct opposite, meaning 'I didn't know that...' or 'I had no idea that...'. It expresses surprise at discovering a new fact, whereas
-ㄴ/는/ㄹ 줄 알았다expresses a pre-existing (and often wrong) assumption. - -ㄴ/는/ㄹ 것 같다Seems Like, Looks Like
-ㄴ/는/ㄹ 것 같다('it seems like') expresses a current guess or feeling based on evidence.-ㄴ/는/ㄹ 줄 알았다expresses a firm belief held in the past, which is now being re-evaluated. - -더라고I Saw/heard/felt That
-더라고is used to report something you personally saw, heard, or experienced in the past ('I saw that...'). It's about reporting a past observation, while-ㄴ/는/ㄹ 줄 알았다is about stating a past belief or assumption, regardless of direct observation.