잖아 meaning — the Korean ending that means "you already know this" (28 real examples)

You have heard this one. It is on almost every page of Korean conversation, it appears in 828 lines of the clip scripts behind our shadowing library, and no subtitle has ever translated it for you.

잖아 does not add information to a sentence. It adds a relationship — it tells the listener that what follows is something they already know, or should know, or agreed to earlier.

English does this with tone of voice and a tag: you know, right?, come on. Korean does it with two syllables glued to the verb, and a translator writing subtitles has nowhere to put it. So it disappears, and you never learn it exists.

Every example below is a real line from a Korean idol or variety clip we transcribed, with the translation we wrote for it. They are grouped by who you can say them to, because that is the part a definition will not tell you.

The one thing to understand before the examples

잖아 is a claim about shared knowledge, and that is why it can be warm or rude depending on whether the claim is true.

When the listener really does know, it lands as intimacy — we both know this, I don't have to explain. That is most of what you will hear in the examples below, between people who are close.

When the listener does not know, the same ending lands as an accusation: I already told you. Nothing in the grammar changes. The social result is completely different.

This is why it is one of the first endings learners hear and one of the last they use safely. Recognising it costs a minute. Producing it well means judging what the other person knows, which is not a grammar skill.

One mechanical note. 잖아 attaches to the verb stem, so what you actually see in a sentence is 하잖아, 있잖아, 먹었잖아, 좋잖아 — the ending fused onto whatever came before it. Look for the 잖 rather than for a separate word.

Casual, stating something — 잖아

This is the form you will hear most, and it belongs between people who are close: friends of the same age, members of the same group, someone clearly younger.

Watch what each line is doing. None of them is delivering new information. Each one reaches for something the other person is assumed to hold already — a shared preference, a fact from earlier in the conversation, a rule everyone in the room accepted.

That is also why so many of these lines would sound abrupt in English if you translated them flatly. The English needs you know or come on or a question tag to carry what the two syllables carry.

⚠️ This is the form to recognise and be careful producing. Said to someone senior to you, it is not merely informal — it claims a closeness you may not have.

• 내가 호떡 진짜 사랑하잖아. (saranghajana) — You know I really love hotteok. Literally: 사랑하잖아 is said 사랑하자나.
• 아니 이거 내가 안 했잖아. (haetjana) — But I didn't do it. Literally: 했잖아 is said 핻짜나.
• 간식 다 먹었냐고 물어보잖아 (mureobojana) — I'm asking if you're done eating. Literally: 물어보잖아 is said 무러보자나.
• 가만히 있었으면 안 뽑았잖아 (ppobatjana) — If you stayed quiet I wouldn't have picked you. Literally: 뽑았잖아 is said 뽀받짜나.
• 내가 처음에 너 의심했잖아. (uisimhaetjana) — I suspected you at first. Literally: 의심했잖아 is said 의심핻짜나.
• 일단 한 명을 죽여야 되잖아 (doejana) — We need to get rid of someone, right? Literally: 되잖아 is said 되자나.
• 어차피 누군가 죽여야 되잖아 (doejana) — Somebody needs to go anyway. Literally: 되잖아 is said 되자나.
• 너 마피아잖아 너 마피아잖아 (mapiajana) — You're the mafia, you're the mafia. Literally: 마피아잖아 is said 마피아자나.
• 와 야 나 하는 줄 알았잖아 (aratjana) — I thought you were singing it! Literally: 알았잖아 is said 아랃짜나.
• 호랑이의 시선이 발에 있잖아 (itjana) — The tiger's gaze is on the shoe. Literally: 있잖아 is said 읻짜나.
• 나를 배신하는지 보는 거잖아 (geojana) — he's watching to see if I'll betray him. Literally: 거잖아 is said 거자나.
• 팀 맺자마자 그린볼 뽑았잖아 (ppobatjana) — You picked green right after forming a team. Literally: 뽑았잖아 is said 뽀받짜나.
• '우리 새해 같이 보냈잖아' (bonaetjana) — "We spent New Year's together". Literally: 보냈잖아 is said 보낻짜나.
• 아웃은 안 시키기로 했잖아. (haetjana) — You said you wouldn't put me out. Literally: 했잖아 is said 핻짜나.

Polite, stating something — 잖아요

Add 요 and the same ending becomes usable with strangers, elders, and on camera to an audience.

What is worth noticing is that the politeness marker does not soften the claim. 잖아요 still asserts that the listener knows this. It just wraps that assertion in respect.

So it works beautifully for things genuinely shared with a wide audience — common sense, something stated a moment ago, a fact about the world. It works badly for something only you know, no matter how polite the ending is.

This is the form most useful to a learner in real life. If you take one thing to produce rather than only recognise, take this one.

• 멤버들이 너무 아쉬워했잖아요 (aswiwohaetjanayo) — and the members were so disappointed. Literally: 아쉬워했잖아요 is said 아쉬워핻짜나요.
• 아니 그런데 너무 가잖아요. (gajanayo) — But he's going too far. Literally: 가잖아요 is said 가자나요.
• 형 솔직히 형이 막내잖아요. (mangnaejanayo) — Honestly, you're the youngest. Literally: 막내잖아요 is said 망내자나요.
• 저희 유일하게 지킨 거잖아요 (geojanayo) — This is the only item we've saved. Literally: 거잖아요 is said 거자나요.
• 아니 이거 사람이 아니잖아요 (anijanayo) — These are not people. Literally: 아니잖아요 is said 아니자나요.
• 이게 요새 기구도 나왔잖아요 (nawatjanayo) — There's a machine for this these days. Literally: 나왔잖아요 is said 나왇짜나요.
• 김치 저거 하나 더 있잖아요 (itjanayo) — We have a packet of kimchi left. Literally: 있잖아요 is said 읻짜나요.
• 멍청이 바보라고는 안 하잖아요 (hajanayo) — But you don't say "foolish dummy". Literally: 하잖아요 is said 하자나요.
• 퇴치 전문 업체가 있잖아요 (itjanayo) — have dedicated extermination services. Literally: 있잖아요 is said 읻짜나요.
• 차라리 뒤에서 말하라잖아요 (malharajanayo) — They're saying they'd rather you talk behind their backs. Literally: 말하라잖아요 is said 말하라자나요.
• 좀비가 누군지 모르잖아요. (moreujanayo) — You don't know who the zombie is. Literally: 모르잖아요 is said 모르자나요.
• 좀비가 공격할 수도 있잖아요. (itjanayo) — Zombies can attack you. Literally: 있잖아요 is said 읻짜나요.
• 사람마다 촉이라는 게 있잖아요 (itjanayo) — Everyone has an intuition. Literally: 있잖아요 is said 읻짜나요.
• 저 꿈꾸고 있는 줄 알았잖아요 (aratjanayo) — so I thought I was dreaming. Literally: 알았잖아요 is said 아랃짜나요.

The rest of this set

This page covers 28 of 56. The rest continue here.

• 잖아 — the Korean ending that means "you already know this" (28 real examples) (this page)
• Casual, asking — Korean endings (28 entries)

잖아 vs 거든 — the pair that gets confused

They look like siblings and they do opposite jobs.

잖아 says you know this already. 거든 says you don't know this, so let me tell you. One assumes shared ground, the other supplies missing ground.

That is why swapping them is more than a style error. Using 잖아 for something the listener has never heard tells them they should have known it, and using 거든 for something obvious sounds like you are explaining the sky to them.

A useful test: if you could put as you know in front of the English, 잖아 fits. If you could put the thing is, 거든 fits.

Both appear constantly in the same conversations, which is exactly why the confusion sticks.

Where these examples came from

Every line on this page is from a clip script we wrote for our shadowing tool — Korean variety episodes, self-produced idol content, and live segments, transcribed line by line with our own English rendering.

That matters for one specific reason. Textbook example sentences are built to demonstrate the grammar point, so the ending always arrives in a situation that makes it obvious. Real speech does not cooperate that way, and half of learning an ending like this is meeting it when the situation is not obvious.

The romanization beside each line is the ending's word as it is actually pronounced, calculated with the same engine that runs on our site rather than typed in by hand.

Lines were kept short on purpose. A long line teaches you the sentence; a short one teaches you the ending.

FAQ

What does 잖아 literally mean? It has no clean literal translation, which is why subtitles drop it. Functionally it marks the sentence as something the listener already knows or agreed to — closest to English you know or a tag question.

Is 잖아 rude? Not in itself, but it can land badly. It claims shared knowledge, so using it for something the listener does not actually know reads as I already told you. Between people who are not close, use 잖아요.

What is the difference between 잖아 and 잖아요? Politeness level only — the meaning is identical. 잖아요 is usable with strangers and people senior to you; 잖아 belongs between people who are close.

How is 잖아 different from 거든? They are opposites. 잖아 assumes the listener already knows; 거든 supplies information the listener does not have. Getting them backwards is the most common mistake with this pair.

Should I search 잖아 or jana? Hangul. The romanized form collides with unrelated results, which we measured — janha returns a Seoul subway station before it returns anything about Korean grammar.