-잖아(요) is used to reference shared knowledge or remind someone of something they already know. It means "you know," "obviously," or "as you know."
Structure
Verb/Adjective stem + -잖아(요)
Meaning: "You know that..." / "Obviously..." / "As you know..."
Formation
With Verbs
Stem + -잖아요:
- 가다 → 가잖아요 (you know [I/you] go)
- 먹다 → 먹잖아요 (you know [we] eat)
- 공부하다 → 공부하잖아요 (you know [I] study)
- 알다 → 알잖아요 (you know [that])
With Adjectives
Stem + -잖아요:
- 좋다 → 좋잖아요 (you know it's good)
- 크다 → 크잖아요 (you know it's big)
- 예쁘다 → 예쁘잖아요 (you know it's pretty)
- 비싸다 → 비싸잖아요 (you know it's expensive)
With Nouns + 이다
Noun + (이)잖아요:
- 학생이잖아요 (you know [they're] a student)
- 친구잖아요 (you know [they're] a friend)
- 한국 사람이잖아요 (you know [they're] Korean)
Core Meaning
Shared Knowledge
Reminding of what both know:
- 내일 시험이잖아요 (You know there's an exam tomorrow)
- 비가 오잖아요 (You know it's raining - as you can see)
Contradiction/Reminder
Pointing out what listener seems to forget:
- 돈이 없잖아요 (You know we don't have money - remember?)
- 약속 있잖아요 (You know you have an appointment)
Obvious Facts
Stating the obvious:
- 어려운 거 알잖아요 (You know it's difficult - obviously)
- 위험하잖아요 (You know it's dangerous)
Usage Contexts
Reminding
When other person seems to forget:
- 오늘 월요일이잖아요 (You know today is Monday)
- 벌써 늦었잖아요 (You know we're already late)
- 일찍 일어나야 하잖아요 (You know you have to wake up early)
Explaining Reasons
Justifying based on shared knowledge:
- 돈이 없잖아요. 그래서 못 사요. (You know we have no money. That's why I can't buy it.)
- 피곤하잖아요. 그래서 쉬어야 해요. (You know I'm tired. That's why I need to rest.)
Contradicting
Pointing out contradiction:
- 어제 안 간다고 했잖아요 (You said you wouldn't go yesterday, you know)
- 싫다고 했잖아요 (You said you didn't like it, you know)
Politeness Levels
Polite: -잖아요
Most common form:
- 알잖아요 (you know)
- 비싸잖아요 (you know it's expensive)
Casual: -잖아
With close friends/family:
- 알잖아 (you know)
- 비싸잖아 (you know it's expensive)
Very Casual: -쟎아
Dialectal/very casual:
- 알쟎아
- Less common in standard speech
Common Patterns
알잖아요 (You Know)
Most common usage:
- 내가 바쁜 거 알잖아요 (You know I'm busy)
- 어려운 거 알잖아요 (You know it's difficult)
-(으)니까... -잖아요
Because... you know:
- 바쁘니까 못 가잖아요 (Because I'm busy, you know I can't go)
-잖아요, 그래서...
You know..., so...:
- 늦었잖아요, 그래서 빨리 가야 해요 (You know we're late, so we have to go quickly)
Tone and Nuance
Can Sound Defensive
When reminding/contradicting:
- 어제 말했잖아요! (I told you yesterday, you know!)
- May sound slightly frustrated
Can Be Gentle
When explaining:
- 피곤하잖아요. 좀 쉬세요. (You know you're tired. Please rest.)
Context Matters
Tone determines whether it's:
- Friendly reminder
- Frustrated correction
- Gentle explanation
Example Dialogues
Dialogue 1: Reminder
A: 영화 보러 갈까요? (Shall we go watch a movie?)
B: 오늘 시험 있잖아요. (You know we have an exam today.)
Dialogue 2: Contradiction
A: 이거 사고 싶어요. (I want to buy this.)
B: 비싸잖아요. 다음에 사요. (You know it's expensive. Let's buy it next time.)
Dialogue 3: Explanation
A: 왜 안 와요? (Why aren't you coming?)
B: 바쁘잖아요. 나중에 갈게요. (You know I'm busy. I'll go later.)
Dialogue 4: Obvious Fact
A: 지금 출발할까요? (Shall we leave now?)
B: 비 오잖아요. 조금 기다려요. (You know it's raining. Let's wait a bit.)
With Different Tenses
Present: -잖아요
Current/general truth:
- 좋잖아요 (you know it's good)
- 가잖아요 (you know [they] go)
Past: -았/었잖아요
Past shared knowledge:
- 어제 갔잖아요 (you know [we] went yesterday)
- 말했잖아요 (you know [I] said)
- 좋았잖아요 (you know it was good)
Future: -(으)ㄹ 거잖아요
Future shared knowledge:
- 갈 거잖아요 (you know [they]'ll go)
- 올 거잖아요 (you know [they]'ll come)
Negative Form
안/못 + Verb + -잖아요
Negative shared knowledge:
- 안 가잖아요 (you know [they] don't go)
- 못 먹잖아요 (you know [they] can't eat)
- 안 좋잖아요 (you know it's not good)
-지 않잖아요
Formal negative:
- 가지 않잖아요 (you know [they] don't go)
- 좋지 않잖아요 (you know it's not good)
Common Expressions
Daily Reminders
- 알잖아요 (you know)
- 바쁘잖아요 (you know I'm/you're busy)
- 시간 없잖아요 (you know we have no time)
- 내일이잖아요 (you know it's tomorrow)
Obvious Facts
- 어렵잖아요 (you know it's hard)
- 비싸잖아요 (you know it's expensive)
- 위험하잖아요 (you know it's dangerous)
- 멀잖아요 (you know it's far)
Contradictions
- 어제 말했잖아요 (you know I said yesterday)
- 안 된다고 했잖아요 (you know [they] said it's not possible)
Special Patterns
그거 알잖아요 (You Know That)
Referencing specific knowledge:
- 그거 알잖아요, 그 영화 말이에요 (You know, that movie I mean)
뭐... -잖아요 (Well... You Know)
Hesitant explanation:
- 뭐... 바쁘잖아요 (Well... you know I'm busy)
Common Mistakes
❌ Incorrect: 가지 않아요잖아요
Double negation structure
✅ Correct: 안 가잖아요 OR 가지 않잖아요
Use one negation pattern
❌ Incorrect: 학생잖아요
Missing 이 for noun
✅ Correct: 학생이잖아요
Add 이 after consonant-ending noun
Cultural Notes
Korean Communication Style
Assumes shared context:
- Koreans often reference shared knowledge
- -잖아요 is very natural in conversation
- Shows connection between speakers
Can Show Closeness
Indicates relationship:
- Using -잖아요 assumes shared knowledge
- Shows familiarity with listener
-잖아요 vs -죠
-잖아요
Reminding/contradiction:
- 알잖아요 (You know - reminder)
- Assumes listener knows but may have forgotten
-죠
Seeking agreement:
- 알죠? (You know, right? - seeking confirmation)
- Checking if listener knows
Different nuance
Summary Table
| Pattern | Example | Meaning |
|---|---|---|
| Verb + 잖아요 | 가잖아요 | you know [they] go |
| Adj + 잖아요 | 좋잖아요 | you know it's good |
| Noun + 이잖아요 | 학생이잖아요 | you know [they're] a student |
| Past + 잖아요 | 갔잖아요 | you know [they] went |
| Negative | 안 가잖아요 | you know [they] don't go |
Key Takeaways
- ✅ Shared knowledge: References what both people know
- ✅ Reminder: Points out what listener may forget
- ✅ Can be defensive: Tone matters
- ✅ Very common: Natural in Korean conversation
- ✅ Shows connection: Assumes familiarity
- ✅ All tenses: Works with present, past, future
-잖아요 is essential for natural Korean conversation, allowing you to reference shared knowledge, remind gently (or firmly), and create connection through assumed common understanding.