Know how to

This pattern is used to express whether you have the ability or know-how to perform a certain action.

Meaning & Usage

Meaning: It translates to "to know how to do (something)" or "to not know how to do (something)."

When to use: Use it when talking about skills, abilities, or methods. This can range from practical skills like driving and cooking to more abstract ones like reading social cues.

Formation

This pattern attaches to verb stems.

Vowel or ㄹ ending stem + ㄹ 줄 알다/모르다:

가다 (to go) → 갈 줄 알다

만들다 (to make) → 만들 줄 알다

Consonant ending stem + 을 줄 알다/모르다:

먹다 (to eat) → 먹을 줄 알다

읽다 (to read) → 읽을 줄 알다

운전할 줄 알아? / 요리할 줄 몰라. / 김치 만들 줄 알아요. / 한자 읽을 줄 알아요?

Learners often confuse -(으)ㄹ 줄 알다 with a similar-looking pattern, -는 줄 알다. Their meanings are completely different.

-(으)ㄹ 줄 알다: Ability/Skill

This pattern is about knowing how to do something.

Example: 피아노 칠 줄 알아요.

Meaning: I know how to play the piano. (I have the skill.)

-는 줄 알다: Assumption/Belief

This pattern is about thinking or assuming that something is the case. It's often used in the past tense (-는 줄 알았다) to mean "I thought that..."

Example: 피아노 치는 줄 알았어요.

Meaning: I thought you were playing the piano / I thought you played the piano. (My assumption was that you play.)

Remember: -(으)ㄹ 줄 is for skill, while -는 줄 is for a belief or assumption about a situation.

한국어 할 줄 알아. / 네가 한국어 하는 줄 알았어. / 그 사람이 운전할 줄 몰라요. / 그 사람이 운전 안 하는 줄 알았어요.

The politeness level of this pattern is determined by the ending of the final verb, 알다 (to know) or 모르다 (to not know).

Casual Form (반말)

Ending: -아/어

Forms: -(으)ㄹ 줄 알아 / -(으)ㄹ 줄 몰라

Usage: Used with close friends, family, and people younger than you. It's informal and friendly.

Polite Form (해요체)

Ending: -아요/어요

Forms: -(으)ㄹ 줄 알아요 / -(으)ㄹ 줄 몰라요

Usage: This is the standard polite form for most daily conversations with strangers, colleagues, or anyone you need to show respect to.

수영할 줄 알아? / 수영할 줄 알아요? / 자전거 탈 줄 몰라. / 자전거 탈 줄 몰라요.