English has two little words — whether and if — that turn a question into something you can slot into a bigger sentence: I don't know *whether he's coming, tell me **if it's true. Korean has no such word. Instead it wraps the whole question in the ending *-지 (with an attributive before it) and treats the result as a noun-like clause — an argument you can feed to verbs of knowing, wondering, and checking, and can even mark with a case particle. Choosing the right shape (-는지 for verbs, -(으)ㄴ지 for adjectives, -(으)ㄹ지 for an open future choice) is the whole skill, and it hinges on the same attributive logic that runs through Korean modification.
The core frame: [question] + -지 + 알다/모르다/궁금하다
Embed a question by ending its clause with -지 and handing it to a matrix verb — most often 알다 ("know"), 모르다 ("not know"), 궁금하다 ("be curious"), 확인하다 ("check"), or 물어보다 ("ask, find out"). Crucially, any wh-word (어디, 뭐, 언제, 왜) stays exactly where it sits in a normal sentence — Korean never fronts it.
화장실이 어디 있는지 알아요?
hwajangsiri eodi inneunji arayo?
Do you know where the bathroom is?
지금 몇 시인지 아세요?
jigeum myeot si-inji aseyo?
Do you know what time it is now?
이 답이 맞는지 확인해 주세요.
i dabi manneunji hwaginhae juseyo.
Please check whether this answer is correct.
The magic is that -지 turns the question into a self-contained noun clause. You are not asking the question — you are naming it as the thing you know, don't know, or are curious about. That is why 알아요? ("do you know?") can take it as its object.
Choosing the attributive: -는지 vs -(으)ㄴ지 vs -인지
The form right before -지 is an attributive ending, and it follows the same verb/adjective split you use for modifying nouns. Get this table into your bones:
| Predicate type | Present ending | Example |
|---|---|---|
| Action verb | -는지 | 가는지, 있는지 |
| Adjective (descriptive verb) | -(으)ㄴ지 | 좋은지, 예쁜지 |
| Copula 이다 | -인지 | 학생인지, 몇 시인지 |
| Past (any predicate) | -았/었는지 | 갔는지, 먹었는지 |
| Future / open choice | -(으)ㄹ지 | 갈지, 뭐 먹을지 |
이 김치가 매운지 아세요?
i gimchiga maeunji aseyo?
Do you know if this kimchi is spicy? (adjective 맵다 → 매운지)
어느 게 더 좋은지 잘 모르겠어요.
eoneu ge deo joeunji jal moreugesseoyo.
I'm honestly not sure which one is better. (adjective 좋다 → 좋은지)
어제 왜 안 왔는지 물어봤어요.
eoje wae an wanneunji mureobwasseoyo.
I asked why he didn't come yesterday. (past 왔다 → 왔는지)
-(으)ㄹ지: the open future choice
-(으)ㄹ지 stands slightly apart. Built on the prospective attributive -(으)ㄹ, it does not merely embed a fact — it flags deliberation or uncertainty about something not yet settled, usually a future course of action. Use -ㄹ지 after a vowel or ㄹ-stem (갈지, 할지) and -을지 after a consonant (먹을지, 있을지).
내일 비가 올지 안 올지 몰라요.
naeil biga olji an olji mollayo.
I don't know whether it'll rain tomorrow or not.
점심에 뭐 먹을지 아직 못 정했어요.
jeomsime mwo meogeulji ajik mot jeonghaesseoyo.
I haven't decided what to eat for lunch yet.
회사를 그만둘지 말지 고민이에요.
hoesareul geumandulji malji gomin-ieyo.
I'm torn about whether to quit my job or not.
The difference between -는지 and -(으)ㄹ지 is realis vs irrealis. 뭐 먹는지 알아요 asks about an existing fact ("do you know what he eats/is eating?"); 뭐 먹을지 정했어요 concerns a choice still hanging in the air ("have you decided what to eat?"). When the sentence is about picking, planning, or predicting — anything unresolved — reach for -(으)ㄹ지. This is the same -(으)ㄹ지 that pairs with -기로 하다 on embedded decisions.
The clause is a full noun — you can case-mark it
Because -지 produces a noun-like clause, it can take a case particle just like any noun. You will often see -지를, -지는, or -지가 when the embedded question is the object or topic of the main verb. This is impossible in English, where an embedded question can never carry a case marker.
뭐 할지를 먼저 정하세요.
mwo haljireul meonjeo jeonghaseyo.
Decide first what you're going to do. (object-marked -지를)
그 사람이 왜 화가 났는지가 제일 궁금해요.
geu sarami wae hwaga nanneunjiga jeil gunggeumhaeyo.
What I'm most curious about is why he got angry. (subject-marked -지가)
-는지 (embedded) vs -냐고 (reported): who is asking?
This is the distinction learners most often blur. -는지 embeds a question inside your own mental verb — you know it, don't know it, or wonder about it. -냐고 (reported question with -냐고) reports that someone actually posed the question out loud.
친구가 가는지 안 가는지 몰라요.
chinguga ganeunji an ganeunji mollayo.
I don't know whether my friend is going or not. (embedded — I wonder)
친구가 저한테 어디 가냐고 물었어요.
chinguga jeohante eodi ganyago mureosseoyo.
My friend asked me where I was going. (reported — an actual question was asked)
Same underlying "going?", opposite jobs: 가는지 is a question you hold in your mind, 가냐고 is a question someone spoke. If nobody literally asked, you want -는지, not -냐고.
Common Mistakes
Mistake 1 — Using reported -냐고 for a mental "wonder / know whether." No one asked the question aloud, so -냐고 is wrong; embed with -는지.
❌ 그 사람이 어디 사냐고 몰라요.
Wrong — nobody asked; a question held in your own mind takes 사는지, not 사냐고.
✅ 그 사람이 어디 사는지 몰라요.
geu sarami eodi saneunji mollayo.
I don't know where that person lives.
Mistake 2 — Wrong attributive: verb -는지 vs adjective -(으)ㄴ지. Match the ending to the predicate type; a verb takes -는지, an adjective takes -(으)ㄴ지.
❌ 이 답이 맞은지 모르겠어요.
Wrong — 맞다 is a verb, so it needs 맞는지, not the adjective form 맞은지.
✅ 이 답이 맞는지 모르겠어요.
i dabi manneunji moreugesseoyo.
I'm not sure whether this answer is right.
Mistake 3 — Using -는지 for a future choice that needs -(으)ㄹ지. A not-yet-made decision is irrealis; -는지 would ask about an existing fact.
❌ 주말에 뭐 하는지 아직 안 정했어요.
Wrong — this asks 'what he does,' but you mean an undecided plan; use 뭐 할지.
✅ 주말에 뭐 할지 아직 안 정했어요.
jumare mwo halji ajik an jeonghaesseoyo.
I haven't decided what to do this weekend yet.
Mistake 4 — Inserting a separate "if / whether" word. There is no standalone word for "whether"; it is the -지 suffix. In particular, 만약 ("if") belongs to real conditionals (-(으)면), not embedded questions.
❌ 만약 그 사람이 오는지 몰라요.
Wrong — 만약 is for conditionals; 'whether he comes' is carried by 오는지 alone.
✅ 그 사람이 오는지 안 오는지 몰라요.
geu sarami oneunji an oneunji mollayo.
I don't know whether he's coming or not.
Key Takeaways
- Embed a question with [clause] + -지, then feed it to 알다 / 모르다 / 궁금하다 / 확인하다 / 물어보다. Wh-words stay in situ.
- Match the attributive to the predicate: verbs -는지, adjectives -(으)ㄴ지, copula -인지, past -았/었는지.
- -(으)ㄹ지 flags an open, unresolved future choice (갈지 말지 고민이에요) — realis -는지 vs irrealis -(으)ㄹ지.
- The -지 clause is a full noun and can be case-marked (뭐 할지를 정하세요).
- -는지 = a question in your mind; -냐고 = a question someone spoke. Don't use -냐고 unless it was actually asked.
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Start learning Korean→Related Topics
- Reported Questions: -냐고 하다TOPIK 3 — Reporting a question in Korean — plain clause + 냐고 + 묻다/물어보다 — with modern Korean leveling verbs, adjectives and 있다/없다 all to bare -냐고; plus why a reported question (someone actually asked) differs from an embedded 'whether' clause with -는지.
- Embedded Decisions: -기로 하다 vs -(으)ㄹ지TOPIK 4 — Two ways Korean embeds a decision — -기로 하다 for a settled resolution ('decide/promise/resolve to') and -(으)ㄹ지 for an open deliberation ('whether/what to') — and why swapping them flips 'settled' and 'unsettled'.
- The Fact That: -(느)ㄴ다는 것 / -다는TOPIK 4 — How Korean says 'the fact / news / idea THAT S' — fusing an indirect-quote clause with a head noun via -다는 (from -다고 하는), the noun-complement cousin of the relative clause.
- The -는 것 Nominalizer (the general-purpose one)TOPIK 2 — -는 것 is the everyday, all-purpose clause nominalizer — attach an attributive ending plus 것 to turn a whole clause into a noun phrase (운동하는 것이 중요해요), conjugating for tense on the attributive and contracting to 거/게/걸/건 in speech.
- Embedded Questions: -(으)ㄴ지 / -는지 아세요?TOPIK 3 — How a question becomes a noun clause tucked under 알다, 모르다, 궁금하다, or 물어보다 with -(으)ㄴ지/-는지 — with the wh-word staying in place and the clause staying SOV.