Learning how to use ‘(으)ㄹ 줄 알다/모르다’ in Korean is essential for expressing knowledge or ability. This grammar pattern helps you talk about what you know how to do or don’t know how to do. Understanding ‘(으)ㄹ 줄 알다/모르다’ allows you to communicate abilities clearly in daily conversations, making your Korean sound more natural.
Contents
1. Definition
he grammar pattern (으)ㄹ줄 알다/모르다 is used to indicate whether someone knows how to do something or not.
- English equivalents: “know how to,” “don’t know how to”
- Basic meaning:
- (으)ㄹ 줄 알다 = to know how to do something
- (으)ㄹ 줄 모르다 = to not know how to do something
2. Form (Structure)
How to Attach
This grammar pattern only attaches to verbs. It cannot be used with adjectives or nouns.
- If the verb stem ends with a consonant: add -을 줄 알다/모르다
- 읽다 → 읽을 줄 알다 (to know how to read)
- 잡다 → 잡을 줄 모르다 (not know how to catch)
- If the verb stem ends with a vowel: add -ㄹ 줄 알다/모르다
- 가다 → 갈 줄 알다 (to know how to go)
- 서다 → 설 줄 모르다 (not know how to stand)
- If the verb stem ends with ㄹ: drop ㄹ and add – 줄 알다/모르다
- 살다 → 살 줄 알다 (to know how to live)
- 알다 → 알 줄 모르다 (not know how / not aware of)
3. Meaning & Usage
1. Expressing Knowledge or Skill
Used when someone knows or does not know how to perform an action.
- 한국어를 할 줄 알아요. (I know how to speak Korean.)
- 피아노를 칠 줄 몰라요. (I don’t know how to play the piano.)
- 자전거를 탈 줄 알아요. (I know how to ride a bicycle.)
- 요리를 할 줄 몰라요. (I don’t know how to cook.)
- 영어를 읽을 줄 알아요. (I know how to read English.)
2. Expressing Inability or Lack of Skill
Used to emphasize when someone cannot do something.
- 운전할 줄 몰라요. (I don’t know how to drive.)
- 컴퓨터를 고칠 줄 몰라요. (I can’t fix a computer.)
- 바둑을 둘 줄 몰라요. (I don’t know how to play baduk.)
- 노래를 부를 줄 몰라요. (I can’t sing a song.)
- 수영을 할 줄 몰라요. (I don’t know how to swim.)
3. Expressing Surprise About Ability
Sometimes used when discovering or being surprised that someone has (or doesn’t have) a skill.
- 그 사람이 춤출 줄 알았어요. (I thought he could dance.)
- 아이가 노래할 줄 몰랐어요. (I didn’t know the child could sing.)
- 친구가 요리할 줄 아는지 몰랐어요. (I didn’t know my friend could cook.)
- 그가 중국어를 할 줄 아는 줄 몰랐어요. (I didn’t know he knew Chinese.)
- 할머니가 스마트폰을 사용할 줄 아셔서 놀랐어요. (I was surprised that my grandmother knows how to use a smartphone.)
4. Key Points to Remember
- Always attach (으)ㄹ 줄 알다/모르다 only to verbs (not adjectives).
- For ㄹ-ending verbs, remove ㄹ before attaching 줄 알다/모르다.
- Apply past, present, and future tense correctly depending on context.
- Use with nouns only when combined with 하다 verbs (e.g., 수영하다, 공부하다).
- This grammar expresses knowledge or ability, not assumptions like -(으)ㄴ 줄 알다.
4. Practice Exercises
Fill in the blanks with the correct form of ‘(으)ㄹ 줄 알다/모르다’:
- 나는 자전거를 ______. (I know how to ride a bicycle.)
- 그는 피아노를 ______. (He doesn’t know how to play the piano.)
- 우리는 한국어를 ______. (We know how to speak Korean.)
- 그녀는 요리를 ______. (She doesn’t know how to cook.)
- 너는 수영을 ______? (Do you know how to swim?)
- 아이가 젓가락을 ______. (The child doesn’t know how to use chopsticks.)
- 나는 바느질을 ______. (I know how to sew.)
- 그는 기타를 ______. (He knows how to play the guitar.)
- 우리는 춤을 ______. (We don’t know how to dance.)
- 어머니는 스마트폰을 ______. (My mother knows how to use a smartphone.)
5. Answers
- 탈 줄 알아요
- 칠 줄 몰라요
- 할 줄 알아요
- 할 줄 몰라요
- 할 줄 아니?
- 사용할 줄 몰라요
- 할 줄 알아요
- 연주할 줄 알아요
- 출 줄 몰라요
- 사용할 줄 알아요
6. Common Mistakes and Tips
⚠️ Mistake 1: Confusing ‘(으)ㄹ 줄 알다’ with ‘(으)ㄹ 수 있다’
Often learners confuse these two expressions. Both look similar but the nuance is different.
- Confusing Example: 저는 피아노를 칠 수 있어요. ❌ (I can play the piano.)
- Correct (when expressing knowledge/skill): 저는 피아노를 칠 줄 알아요. ✅ (I know how to play the piano.)
💡 Tip: Use (으)ㄹ 줄 알다 when expressing knowledge or learned skill, and use (으)ㄹ 수 있다 when expressing general capability, possibility, or condition.
📍 Want to learn more about the difference between ‘(으)ㄹ 줄 알다/ 모르다’ and ‘(으)ㄹ 수 있다‘? Understanding this distinction can take your Korean fluency to the next level!
Click below 👇👇👇 to learn more!”
⚠️ Mistake 2: Using 는 instead of (으)ㄹ
Incorrect: 저는 요리하는 줄 알아요. ❌ (I know cooking.)
Correct: 저는 요리할 줄 알아요. ✅ (I know how to cook.)
💡 Tip: Always use ‘(으)ㄹ’ to indicate future or potential action when expressing knowledge of how to do something.
⚠️ Mistake 3: Forgetting to adjust for vowel/consonant endings
Incorrect: 저는 노래을 줄 알아요. ❌ (I know how to sing.)
Correct: 저는 노래할 줄 알아요. ✅ (I know how to sing.)
💡 Tip: Use ‘을’ after consonants and ‘ㄹ’ after vowels when applying the ‘(으)ㄹ’ rule.
The grammar ‘-(으)ㄹ 줄 알다/모르다’ is a powerful tool for expressing knowledge and ability in Korean. It helps you describe what you can or cannot do, and even show surprise in certain situations. By mastering this pattern, you will become more confident in everyday conversations. Use it to share your skills, abilities, and what you are still learning to do.