-ㄴ/는/ㄹ 줄 모르다

How It Works

Examples (5)

1. 저는 운전할 줄 몰라요.

   I don't know how to drive.

   Word by Word: I driving-how-to don't-know.

   This example uses the 'inability' meaning. It always uses the -(으)ㄹ form.

2. 한국어 공부가 이렇게 재미있는 줄 몰랐어요.

   I didn't know studying Korean was this fun.

   Word by Word: Korean study this-much fun-is-fact didn't-know.

   This shows the 'unawareness' meaning with an adjective (재미있다). The -ㄴ ending is used for present tense adjectives.

3. 친구가 벌써 집에 간 줄 몰랐어요.

   I didn't know my friend had already gone home.

   Word by Word: Friend already home went-fact didn't-know.

   This shows the 'unawareness' meaning with a past tense action verb (가다 -> 간).

4. 밖에 비가 오는 줄 몰랐어요.

   I didn't know it was raining outside.

   Word by Word: Outside rain is-coming-fact didn't-know.

   This shows 'unawareness' of a present, ongoing action (오다 -> 오는).

5. 그 사람이 의사인 줄 몰랐어요.

   I didn't know that person was a doctor.

   Word by Word: That person doctor-is-fact didn't-know.

   This shows 'unawareness' with a noun + 이다.

Common Mistakes

• Using the wrong conjugation for 'not knowing how to do something'. For inability, you must always use -(으)ㄹ 줄 모르다.

  Not Quite저는 수영하는 줄 몰라요.

  Better저는 수영할 줄 몰라요.

  When expressing a lack of skill or ability, the future tense form -(으)ㄹ is always used before 줄 모르다. The form -는 줄 몰라요 would mean 'I didn't know that you are swimming right now'.

• Confusing -ㄴ/는/ㄹ 줄 모르다 (unawareness of a fact) with -ㄴ/는/ㄹ지 모르다 (uncertainty or wondering about something).

  Not Quite그 사람이 언제 올 줄 몰라요.

  Better그 사람이 언제 올지 몰라요.

  -ㄴ/는/ㄹ 줄 모르다 is used when you are unaware of a supposed fact. -ㄴ/는/ㄹ지 모르다 is used when you are uncertain or wondering about something, often with question words like 언제 (when), 어디 (where), or 뭐 (what). The correct sentence means 'I don't know when he will come'.

Learn This First

To express 'don't know how to/be unaware that', you need modifier forms and negation.

• -ㄴ/는/ㄹModifier Endings

  This uses various modifier forms for different tenses.

• Negation patterns

  This uses 모르다 to express lack of knowledge.

Related Patterns

• -ㄴ/는/ㄹ 줄 알다Know How to, Be Aware That

  This is the direct opposite, meaning 'to know how to do something' or 'to be aware that something is the case'. They share the exact same conjugation rules.

• -ㄴ/는/ㄹ지 알다/모르다(Don't) Know If/whether

  This pattern expresses uncertainty about a piece of information (if/whether/what/when). While -줄 모르다 means being unaware of a fact, -지 모르다 means not knowing the answer to a question (e.g., 'I don't know WHEN he will come').

• -(으)ㄹ 수 있다/없다Can/cannot

  While -ㄹ 줄 모르다 means 'not knowing how to', -ㄹ 수 없다 means 'cannot' due to a lack of ability or external circumstances. They are often interchangeable for ability, but -ㄹ 수 없다 is broader.

• -는 것Thing of -ing

  Both patterns use a noun (-것 or -줄) to turn a preceding clause into a noun phrase that can be the object of a verb like 알다 or 모르다. -는 것 means 'the act of/fact that', while -는 줄 refers to a supposed fact or method.

Learn Next

Patterns that build on this one.

• -ㄴ/는/ㄹ 줄 몰랐다I Didn’t Know That…, I Had No Idea That…

Words in This Pattern