잘 자
jal ja
The English phrase "night night" is translated into Korean as 잘 자 (jal ja).
잘 자 is a simple and casual way to say "sleep well" to a friend or peer. In close relationships, you can say Saranghae before 잘 자 to express affection.
Is there a formal and an informal way to say it?
잘 자 is an informal expression used with friends, siblings or people younger than you. For a polite way to wish someone a good night's sleep, you can use 잘 주무세요, which literally translates to "sleep well". When speaking to elders or in formal settings, you should use 안녕히 주무세요 instead of 잘 자.
How does it change in a sentence?
Adding the polite particle 요 (yo) to 잘 자 makes it 잘 자요, which is a polite way to say "sleep well" to someone you are not on close, informal terms with.
Did you know?
- While 잘 자 is the common phrase, the root verb 자다 appeared in the 'Yongbi eocheon'ga', one of the earliest works written in the Hangul script in 1447.
- When saying 잘 자 to children, parents often use a cute style called 'aegyo' by stretching the final vowel to make it sound more affectionate.
- In Korean, the level of politeness for 'good night' is not just about adding a particle, but often requires changing the entire verb from 자다 to the honorific 주무시다, as seen in 안녕히 주무세요.
Examples in context
- 할머니, 잘 주무세요.Grandma, sleep well.
- 민수 씨, 잘 자.Min-su, sleep well.
- 잘 자.jal ja.Night night.
- 내 꿈 꿔, 잘 자.nae kkum kkwo, jal ja.Dream of me, night night.
- 오늘 고생했어, 잘 자.oneul gosaenghaesseo, jal ja.You worked hard today, night night.
Example conversation
Two friends are saying goodbye over the phone late at night.
- 도현 Do-hyeon이제 진짜 자야겠다.ije jinjja jaya-getda.I really should sleep now.
- 지은 Ji-eun그래, 도현아 잘 자.geurae, Dohyeon-ah jal ja.Okay, night night, Dohyeon.
- 도현 Do-hyeon지은이 너도 잘 자.Jieun-i neodo jal ja.Night night to you too, Jieun.
- 지은 Ji-eun응, 내일 봐!eung, naeil bwa!Yeah, see you tomorrow!
Sources
- Pronunciation: Wiktionary entry 잘 자, CC BY-SA 4.0, dump of 2026-09-26.
- Word origins: Wiktionary entries 자, 잘, 잘 자, CC BY-SA 4.0.
