Describes skies or water that are clear, clean, and transparent
When to use
Clear sky, Clear water, Clear mood, Clear voice
The nuance
Use 맑다 only when the sky is mostly cloudless and bright; also used for clear moods or voices
맑다 (mak-da, makda) · 흐리다 (heu-ri-da, heurida)
맑다 generally describes clear, clean, and transparent skies or water, while 흐리다 refers to cloudy, overcast, or gloomy conditions.

One lane per word — no nested boxes, just the gist.
Describes skies or water that are clear, clean, and transparent
When to use
Clear sky, Clear water, Clear mood, Clear voice
The nuance
Use 맑다 only when the sky is mostly cloudless and bright; also used for clear moods or voices
Refers to skies covered with clouds, dark and dull conditions
When to use
Cloudy sky, Cloudy weather, Gloomy mood, Unclear expression
The nuance
Use 흐리다 only when the sky is mostly cloudy or dull; also used for gloomy moods or unclear expressions
하늘이 오늘 정말 맑다.
ha-neul-i o-neul jeong-mal mak-da., ha neul i o neul jeong mal mak da.
Appropriate to describe a sky that is mostly cloudless and bright.
물이 맑아서 물고기가 잘 보여요.
mul-i mak-a-seo mul-go-gi-ga jal bo-yeo-yo., mul i mak a seo mul go gi ga jal bo yeo yo.
Correctly describes water that is transparent and clean.
오늘은 날씨가 흐려서 기분도 흐려요.
o-neul-eun nal-ssi-ga heu-ryeo-seo gi-bun-do heu-ryeo-yo., o neul eun nal ssi ga heu ryeo seo gi bun do heu ryeo yo.
Naturally combines cloudy weather with a gloomy mood.
그의 목소리가 흐려서 듣기 힘들었어요.
geu-ui mok-so-ri-ga heu-ryeo-seo deut-gi him-deul-eoss-eo-yo., geu ui mok so ri ga heu ryeo seo deut gi him deul eoss eo yo.
Voices are described as '맑다' (clear), not '흐리다' (cloudy/dull).
오늘 하늘이 흐려서 별이 잘 보여요.
o-neul ha-neul-i heu-ryeo-seo byeol-i jal bo-yeo-yo., o neul ha neul i heu ryeo seo byeol i jal bo yeo yo.
Stars are not visible in cloudy skies, so this sentence is illogical.
기분이 맑아서 모든 게 잘 풀려요.
gi-bun-i mak-a-seo mo-deun ge jal pul-ryeo-yo., gi bun i mak a seo mo deun ge jal pul ryeo yo.
Use '맑다' to express a fresh and positive mood.
날씨가 맑아서 비가 올 것 같아요.
nal-ssi-ga mak-a-seo bi-ga ol geos gat-a-yo., nal ssi ga mak a seo bi ga ol geos gat a yo.
Clear weather usually means no rain, so this is contradictory.
하늘이 맑아서 구름이 많아요.
ha-neul-i mak-a-seo gu-reum-i man-a-yo., ha neul i mak a seo gu reum i man a yo.
A clear sky cannot have many clouds; this is contradictory.
When is it incorrect to use 맑다?
Which sentence correctly uses 흐리다?
Which sentence misuses 흐리다?