-ㄴ/는/ㄹ지 알다/모르다
(Don't) Know If/whether
This pattern combines an embedded question clause with '알다' (to know) or '모르다' (to not know). It translates to 'I know/don't know if/whether...' or 'I know/don't know who/what/where/when/why/how...'
How It Works
This pattern is essential for expressing uncertainty or asking for information indirectly. The core of this structure is the -ㄴ지/는지 ending, which turns a statement or question into a noun clause representing an unknown piece of information.
How it works:
You take a question (e.g., '누가 왔어요?' - Who came?) and embed it into a larger sentence (e.g., '저는 [누가 왔는지] 몰라요.' - I don't know [who came].).
Conjugation Rules:
The conjugation depends on the type of word and the tense.
1. Adjectives: Attach -ㄴ지 to stems ending in a vowel (e.g., 크다 → 큰지) and -은지 to stems ending in a consonant (e.g., 작다 → 작은지).
• 이 옷이 얼마나 비싼지 알아요? (Do you know how expensive these clothes are?)
2. Verbs (Present Tense): Attach -는지 to the verb stem, regardless of whether it ends in a vowel or consonant.
• 그 사람이 지금 어디에 사는지 몰라요. (I don't know where that person lives now.)
3. Verbs (Past Tense): Attach -았/었는지 to the verb stem.
• 어제 누가 전화했는지 기억이 안 나요. (I don't remember who called yesterday.)
4. Future Tense / Conjecture (Verbs & Adjectives): Attach -ㄹ지 to stems ending in a vowel and -을지 to stems ending in a consonant. This is used for future possibilities or when guessing about something.
• 회의가 언제 끝날지 모르겠어요. (I don't know when the meeting will end.)
5. Nouns (이다/아니다): Attach -인지 to the noun.
• 저 분이 선생님인지 학생인지 잘 모르겠어요. (I'm not sure if that person is a teacher or a student.)
This pattern is frequently used with question words like 누구 (who), 뭐 (what), 어디 (where), 언제 (when), 왜 (why), 어떻게 (how), and 얼마나 (how much/many).
Examples (5)
- 그 사람이 어디에 사는지 알아요?
Do you know where that person lives?
Word by Word: That person where lives do you know?
Uses the present tense verb form '사는지' (from 살다) to ask about a current, unknown fact.
- 내일 날씨가 좋을지 모르겠어요.
I don't know if the weather will be good tomorrow.
Word by Word: Tomorrow weather will be good I don't know.
Uses the future/conjecture form '좋을지' (from 좋다) to express uncertainty about a future event.
- 이 문제가 왜 중요한지 설명해 주세요.
Please explain why this problem is important.
Word by Word: This problem why is important please explain.
Here, the pattern is used with '설명하다' (to explain) instead of '알다/모르다', showing its versatility. It uses the adjective form '중요한지' (from 중요하다).
- 누가 이 케이크를 만들었는지 아는 사람 있어요?
Is there anyone who knows who made this cake?
Word by Word: Who this cake made person who knows is there?
Uses the past tense form '만들었는지' (from 만들다) to ask about a past action.
- 이게 진짜인지 가짜인지 구별할 수 없어요.
I can't distinguish whether this is real or fake.
Word by Word: This real-if fake-if distinguish cannot.
Uses the noun form '진짜인지' and '가짜인지' to express uncertainty between two noun options.
Common Mistakes
Using the present tense '-는지' for future events.
Different Meaning주말에 영화를 보는지 모르겠어요.Better주말에 영화를 볼지 모르겠어요.For future actions or possibilities, you must use the future tense form -(으)ㄹ지. '-는지' is for present tense actions or general facts.
Confusing '-ㄴ/는지' (whether/if) with '-는 것' (the fact that).
Different Meaning저는 지구가 둥근지 알아요.Better저는 지구가 둥글다는 것을 알아요.'-ㄴ/는지 알다' implies you know the answer to a question or uncertainty. For stating knowledge of a definite, established fact, it's more natural to use -는 것 or a quotation form like -다는 것.
Learn This First
To express knowledge/uncertainty about facts, you need modifier forms and question/negation patterns.
Related Patterns
- -ㄴ지/는지Whether, If
This is the core grammatical component that forms the embedded question clause. The target pattern, '-ㄴ/는/ㄹ지 알다/모르다', is a direct application of this clause with the verbs for knowing/not knowing.
- -(으)ㄹ지Whether, If
This is the future/conjecture version of the embedded question clause. It's crucial to distinguish its use for future uncertainty from the present tense '-는지'.
- -ㄴ/는/ㄹ 줄 알다Know How to, Be Aware That
This pattern is very similar in structure but different in meaning. It means 'to know/not know how to do something' or 'to think/assume' something (which may be incorrect). It's often confused with '-ㄴ/는/ㄹ지 알다/모르다', which is about knowing/not knowing a piece of information.
- -ㄴ/는/ㄹ 줄 모르다Not Know How to, Be Unaware That
This pattern is very similar in structure but different in meaning. It means 'to know/not know how to do something' or 'to think/assume' something (which may be incorrect). It's often confused with '-ㄴ/는/ㄹ지 알다/모르다', which is about knowing/not knowing a piece of information.
- -(으)ㄹ까 봐For Fear That, Worried That
Both patterns deal with future uncertainty. However, '-ㄹ지 모르다' is a neutral statement of not knowing, while '-ㄹ까 봐' specifically expresses worry or concern about a possible negative outcome.
- -ㄴ/는/ㄹ 것 같다Seems Like, Looks Like
This pattern is used to express a guess or assumption ('it seems like...'), which is a way of dealing with uncertainty. It contrasts with '-ㄴ/는/ㄹ지 모르다', which explicitly states a lack of knowledge rather than making a guess.