How to Say “Good Night” in Korean: 잘 자 (jal ja)

“Jal ja” literally means “sleep well” — the casual “good night” you text a friend or partner.

잘 자 (jal ja) — good night / sleep well

How it feels and when to use it

To elders or in-laws, use the honorific “jumuseyo” (주무세요, please sleep). Korean has special honorific verbs for sleeping, eating, and being — “jumusida” is the respectful “to sleep.”

Politeness levels

잘 자 (jal ja) — Casual (반말): with close friends and people younger than you
잘 자요 (jal jayo) — Polite (해요체): the safe everyday level for most people
안녕히 주무세요 (annyeonghi jumuseyo) — Formal (합쇼체): in business, announcements, and to elders

Real examples from native Korean

Here’s how native speakers actually use 잘 자 in real Korean:

잘 자~ — Good night~
잘 자른다. — Good.
잘 자 명호~ — Goodnight Myungho~

A common mistake to avoid

Honorific verbs are irregular — You can’t just add a polite ending to “자다.” For elders the verb itself changes to “주무시다.” A few core verbs (sleep, eat, be) work this way — memorize them as pairs.

Related expressions

잘 가 (jal ga) — bye
좋은 꿈 꿔 (joeun kkum kkwo) — sweet dreams

Want to hear 잘 자 spoken by real Koreans? Search it on Langle and watch it across dozens of real video clips.

Frequently asked questions

What does “잘 자” mean in Korean?

“Jal ja” literally means “sleep well” — the casual “good night” you text a friend or partner. It’s romanized as “jal ja.”

Is “잘 자” formal or casual?

“잘 자” is casual (반말); “잘 자요” is polite (해요체); “안녕히 주무세요” is formal (합쇼체). Match the level to who you’re talking to.

How do you pronounce “잘 자”?

It’s pronounced “jal ja.” Honorific verbs are irregular: You can’t just add a polite ending to “자다.” For elders the verb itself changes to “주무시다.” A few core verbs (sleep, eat, be) work this way — memorize them as pairs.

When should I use “잘 자”?

What can I say instead of “잘 자”?

Try “잘 가” (bye) or “좋은 꿈 꿔” (sweet dreams).