Refers to dreams during sleep or hopes for the future.
When to use
dreams during sleep, expressing future hopes, romantic hopes
The nuance
Use 꿈꾸다 for unconscious dreams during sleep or expressing hopes about the future.
꿈꾸다 (kkum-kku-da, kkumkkuda) · 상상하다 (sang-sang-ha-da, sangsanghada)
'꿈꾸다' refers to experiences during sleep or hopes, while '상상하다' means consciously picturing something in your mind.

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Refers to dreams during sleep or hopes for the future.
When to use
dreams during sleep, expressing future hopes, romantic hopes
The nuance
Use 꿈꾸다 for unconscious dreams during sleep or expressing hopes about the future.
Consciously picturing a situation or scene in one's mind.
When to use
conscious image creation, thinking of hypothetical situations, creative thinking
The nuance
Use 상상하다 when consciously visualizing or thinking about something while awake.
나는 어젯밤에 이상한 꿈을 꿈꿨어.
na-neun eo-jes-bam-e i-sang-han kkum-eul kkum-kkwoss-eo., na neun eo jes bam e i sang han kkum eul kkum kkwoss eo.
Use 꿈꾸다 to describe a dream experienced during sleep.
나는 어젯밤에 이상한 상상을 했어.
na-neun eo-jes-bam-e i-sang-han sang-sang-eul haess-eo., na neun eo jes bam e i sang han sang sang eul haess eo.
Do not use 상상하다 for dreams during sleep; use 꿈꾸다 instead.
그는 미래에 큰 성공을 꿈꾼다.
geu-neun mi-rae-e keun seong-gong-eul kkum-kkun-da., geu neun mi rae e keun seong gong eul kkum kkun da.
Use 꿈꾸다 to express hopes or goals for the future.
그는 미래에 큰 성공을 상상한다.
geu-neun mi-rae-e keun seong-gong-eul sang-sang-han-da., geu neun mi rae e keun seong gong eul sang sang han da.
상상하다 can be used to consciously visualize future scenarios.
나는 내일 일어날 일을 꿈꿨어.
na-neun nae-il il-eo-nal il-eul kkum-kkwoss-eo., na neun nae il il eo nal il eul kkum kkwoss eo.
You cannot use 꿈꾸다 for future events you think about while awake; use 상상하다.
나는 내일 일어날 일을 상상했어.
na-neun nae-il il-eo-nal il-eul sang-sang-haess-eo., na neun nae il il eo nal il eul sang sang haess eo.
Use 상상하다 to imagine future events consciously.
작가는 새로운 세계를 상상한다.
jak-ga-neun sae-ro-un se-gye-reul sang-sang-han-da., jak ga neun sae ro un se gye reul sang sang han da.
Use 상상하다 for creative or hypothetical thinking.
작가는 새로운 세계를 꿈꾼다.
jak-ga-neun sae-ro-un se-gye-reul kkum-kkun-da., jak ga neun sae ro un se gye reul kkum kkun da.
꿈꾸다 is inappropriate for conscious creative imagining; use 상상하다.
Which word should be used to describe dreams during sleep?
Which word is appropriate when picturing future events in your mind?
Which word should be used when a writer imagines a new world in their mind?