To physically hide or cover something so others cannot see it.
When to use
Hiding objects, Direct secret concealment, Hiding visible things
The nuance
Used primarily when physically hiding objects or facts directly; suitable for tangible things.
숨기다 (sum-gi-da, sumgida) · 감추다 (gam-chu-da, gamchuda)
'숨기다' focuses on physically or directly hiding something, while '감추다' is used for more subtle or abstract concealment.

One lane per word — no nested boxes, just the gist.
To physically hide or cover something so others cannot see it.
When to use
Hiding objects, Direct secret concealment, Hiding visible things
The nuance
Used primarily when physically hiding objects or facts directly; suitable for tangible things.
To conceal something subtly or make it not appear, used for abstract things like emotions or truths as well.
When to use
Hiding emotions, Concealing truth, Hiding secret intentions
The nuance
Mainly used to subtly hide invisible things like emotions, truths, or intentions; can be used for physical objects but with a more figurative meaning.
그는 비밀을 잘 숨긴다.
geu-neun bi-mil-eul jal sum-gin-da., geu neun bi mil eul jal sum gin da.
'숨기다' fits here because it refers to directly hiding or not revealing a secret.
그는 비밀을 잘 감춘다.
geu-neun bi-mil-eul jal gam-chun-da., geu neun bi mil eul jal gam chun da.
'감추다' is also natural here as it implies subtly concealing a secret.
아이들이 장난감을 감추었다.
a-i-deul-i jang-nan-gam-eul gam-chu-eoss-da., a i deul i jang nan gam eul gam chu eoss da.
'감추다' is incorrect because physical objects like toys are directly hidden, so '숨기다' is appropriate.
아이들이 장난감을 숨겼다.
a-i-deul-i jang-nan-gam-eul sum-gyeoss-da., a i deul i jang nan gam eul sum gyeoss da.
'숨기다' is correct for physically hiding toys.
그녀는 슬픔을 숨기려 애썼다.
geu-nyeo-neun seul-peum-eul sum-gi-ryeo ae-sseoss-da., geu nyeo neun seul peum eul sum gi ryeo ae sseoss da.
'숨기다' is possible but '감추다' is more natural for hiding emotions.
그녀는 슬픔을 감추려 애썼다.
geu-nyeo-neun seul-peum-eul gam-chu-ryeo ae-sseoss-da., geu nyeo neun seul peum eul gam chu ryeo ae sseoss da.
'감추다' is the most suitable for subtly hiding emotions.
그는 진실을 숨겼다.
geu-neun jin-sil-eul sum-gyeoss-da., geu neun jin sil eul sum gyeoss da.
'숨기다' is incorrect because abstract things like truth are better concealed with '감추다'.
그는 진실을 감추었다.
geu-neun jin-sil-eul gam-chu-eoss-da., geu neun jin sil eul gam chu eoss da.
'감추다' fits perfectly for subtly concealing the truth.
Which word should be used when hiding a toy?
Which word is appropriate for subtly hiding emotions?
Which expression fits concealing the truth?