-잖아요: As You Know in Korean

-잖아요 is what Korean speakers use when the listener is expected to already know, remember, or recognize the point.

• 오늘 일요일이잖아요. → It’s Sunday, you know.
• 제가 어제 말했잖아요. → I told you yesterday, remember?
• 비싸잖아요. → It’s expensive, as you know.

Chamelingo has a full -잖아요 reference plus a review page in the grammar encyclopedia.

The core idea: shared knowledge

Instead of memorizing one translation, think:

“I am presenting this as something we both know or should know.”

That can be friendly:

• 우리 친구잖아요. → We’re friends, you know.

Or explanatory:

• 내일 시험이잖아요. 그래서 공부해야 해요. → We have an exam tomorrow, remember, so I have to study.

Or corrective:

• 제가 이미 했잖아요. → I already did it, remember.

The tone changes the social effect.

Why it appears so often in conversation

Korean conversation frequently manages what both speakers know. -잖아요 lets the speaker connect a new point to shared context without explaining everything again.

Example:

A: 왜 일찍 가요? → Why are you leaving early?

B: 내일 일해야 하잖아요. → Because I have to work tomorrow, you know.

The speaker treats “I work tomorrow” as relevant background the listener may already know.

Tone matters

This is the biggest learner warning.

With warm intonation, -잖아요 can create closeness or a “you know what I mean” feeling.

With strong or repeated emphasis, it can sound like:

“I already told you this.”

So do not copy the ending only from subtitles. Listen to how it is delivered and who is speaking to whom.

Compare with -지요 / -죠

• 맞죠? → Right? / That’s right, isn’t it?
• 맞잖아요. → It is right, as you know / Come on, it’s right.

Both can involve shared understanding, but -잖아요 often carries a stronger reminder.

See the core -지요 reference.

Combine it with grammar you already know

• 가고 싶잖아요. → You/I want to go, as we know.
• 해야 하잖아요. → We have to do it, you know.
• 비가 올 거잖아요. → It is going to rain, as you know/expect.

This is why conversational endings become more useful after your basic tense and obligation patterns are stable.

Common mistake: using it for brand-new information

If the listener has no reason to know the information, plain statement endings are usually safer.

Do not use -잖아요 just because English says “you know” as a filler. Korean -잖아요 carries a real shared-knowledge assumption.

Mini practice

What feeling fits best?

1. 오늘 휴일이잖아요. → reminder/shared fact
2. 제가 말했잖아요. → reminder, possibly corrective
3. 우리 친구잖아요. → shared relationship, potentially warm
4. 너무 멀잖아요. → presenting the distance as obvious/relevant

Continue learning

• -잖아요 reference
• -지요 confirmation
• -는데
• -아/어야 해요
• Speaking guides

Treat -잖아요 as a relationship-and-context ending, not merely vocabulary. That is what makes it sound natural rather than pasted onto a sentence.