Indicates the act or state of sleeping.
When to use
Sleeping state, Napping, Sleeping at night
The nuance
'자다' is used only when someone is sleeping; it cannot be used to describe waking up.
자다 (ja-da, jada) · 깨다 (kkae-da, kkaeda)
'자다' means to be sleeping, while '깨다' means to wake up from sleep.

One lane per word — no nested boxes, just the gist.
Indicates the act or state of sleeping.
When to use
Sleeping state, Napping, Sleeping at night
The nuance
'자다' is used only when someone is sleeping; it cannot be used to describe waking up.
Indicates the act or state of waking up from sleep.
When to use
Waking up from sleep, Getting up in the morning, Brief awakening
The nuance
'깨다' is used to express the moment of waking up or being awake after sleep.
나는 밤새 잘 잤다.
na-neun bam-sae jal jass-da., na neun bam sae jal jass da.
Appropriate sentence expressing the state of sleeping.
나는 밤새 깨었다.
na-neun bam-sae kkae-eoss-da., na neun bam sae kkae eoss da.
'깨다' means the moment of waking up, so it is incorrect to say '깨었다' to mean being awake all night; use '깨어 있었다' instead.
아침에 일찍 깨서 운동했다.
a-chim-e il-jjik kkae-seo un-dong-haess-da., a chim e il jjik kkae seo un dong haess da.
Correct usage to express waking up and then doing something.
그는 지금 자고 있다.
geu-neun ji-geum ja-go iss-da., geu neun ji geum ja go iss da.
Correct expression for currently sleeping.
나는 낮잠을 깨고 싶다.
na-neun naj-jam-eul kkae-go sip-da., na neun naj jam eul kkae go sip da.
'깨다' means to wake up, so '낮잠을 깨고 싶다' is unnatural; correct forms are '낮잠에서 깨고 싶다' or '일어나고 싶다'.
잠이 들기 전에 깨 있었다.
jam-i deul-gi jeon-e kkae iss-eoss-da., jam i deul gi jeon e kkae iss eoss da.
Properly expresses being awake before falling asleep.
나는 자고 나서 기분이 좋아졌다.
na-neun ja-go na-seo gi-bun-i joh-a-jyeoss-da., na neun ja go na seo gi bun i joh a jyeoss da.
Sentence correctly shows change after sleeping.
그는 갑자기 깨서 소리를 질렀다.
geu-neun gap-ja-gi kkae-seo so-ri-reul jil-reoss-da., geu neun gap ja gi kkae seo so ri reul jil reoss da.
Appropriate to express sudden waking up.
Which sentence correctly uses '깨다'?
Which sentence cannot use '자다'?
What does '깨다' mean?
What does it mean?