Core Grammar Rule: ~는지 알다/모르다
This pattern is used to embed a question about a piece of information into a larger sentence, typically to ask if someone knows (알다) or doesn't know (모르다) that information. It's the Korean equivalent of "Do you know where/what/when/if...".
Meaning & Usage
Meaning: It connects a clause containing a question word (like 언제 when, 어디 where, 누구 who, 무엇 what, 어떻게 how, 왜 why) or an uncertain situation to the verbs 알다 (to know) or 모르다 (to not know).
When to use: Use it when you're not asking a direct yes/no question, but rather asking about the content of the question itself. For example, instead of asking "Is the bank open?" you ask "Do you know what time the bank closes?".
Conjugation Rules
Verbs: Attach ~는지 directly to the verb stem, regardless of whether it ends in a vowel or a consonant.
가다 (to go) → 가는지
먹다 (to eat) → 먹는지
Adjectives: Attach ~(으)ㄴ지. If the stem ends in a vowel, add ~ㄴ지. If it ends in a consonant, add ~은지.
예쁘다 (to be pretty) → 예쁜지
작다 (to be small) → 작은지
Nouns (이다): Attach ~인지 to the noun.
학생 (student) → 학생인지
의사 (doctor) → 의사인지
Verb: ~는지 / Adjective: ~(으)ㄴ지 / Noun: ~인지
Native Nuance & Mistakes
To sound more natural, it's important to use this pattern correctly and avoid common pitfalls, especially regarding politeness and sentence structure.
Use 모르겠어요 instead of 몰라요
Context: When you don't know the answer to a question in a polite conversation, saying 몰라요 can sound a bit blunt or cold. Natives much more commonly use 모르겠어요 or 잘 모르겠어요 (I'm not quite sure). This softens the response and makes you sound more considerate.
Example: "이 근처에 은행이 어디에 있는지 아세요?" (Do you know where a bank is near here?) → "죄송해요. 잘 모르겠어요." (I'm sorry. I'm not sure.) is more natural than "몰라요." (I don't know.)
Don't Confuse with Simple Noun + 알다/모르다
Context: ~는지 알다 is for knowing information about something, not just knowing the thing itself. For example, 민수씨를 알아요? means "Do you know Minsu?". But 민수씨가 어디에 사는지 알아요? means "Do you know where Minsu lives?". A common mistake is to mix these up. You can't say 민수씨가 어디에 살아요 알아요? (X). The question part must be converted into the ~는지 clause.