못 (mos) · 안 (an)
못 and 안 both express negation, but 못 emphasizes 'inability or impossibility,' while 안 stresses 'intentional negation.'
One lane per word — no nested boxes, just the gist.
Indicates inability or impossibility to perform an action due to ability or circumstances
When to use
lack of ability, situational impossibility, external constraint
The nuance
못 is used mainly to express situations where an action is impossible due to lack of ability or circumstances, regardless of intention.
Expresses intentional negation or refusal to perform an action
When to use
intentional negation, selective refusal, habitual negation
The nuance
안 indicates that the speaker intentionally chooses not to do something, regardless of ability.
나는 수영을 못 해요.
na-neun su-yeong-eul mos hae-yo., na neun su yeong eul mos hae yo.
Correct use of 못 to indicate inability to swim.
나는 수영을 안 해요.
na-neun su-yeong-eul an hae-yo., na neun su yeong eul an hae yo.
Correct use of 안 to express intentional choice not to swim.
나는 어제 숙제를 못 했어요.
na-neun eo-je suk-je-reul mos haess-eo-yo., na neun eo je suk je reul mos haess eo yo.
Correct use of 못 to indicate inability to do homework yesterday.
나는 어제 숙제를 안 했어요.
na-neun eo-je suk-je-reul an haess-eo-yo., na neun eo je suk je reul an haess eo yo.
Correct use of 안 to express intentional refusal to do homework yesterday.
나는 피자를 못 좋아해요.
na-neun pi-ja-reul mos joh-a-hae-yo., na neun pi ja reul mos joh a hae yo.
못 is inappropriate for feelings; use 안 좋아해요 instead.
나는 피자를 안 좋아해요.
na-neun pi-ja-reul an joh-a-hae-yo., na neun pi ja reul an joh a hae yo.
Correct use of 안 to express dislike intentionally.
비가 와서 밖에 못 나갔어요.
bi-ga wa-seo bakk-e mos na-gass-eo-yo., bi ga wa seo bakk e mos na gass eo yo.
Correct use of 못 to show situational impossibility due to rain.
비가 와서 밖에 안 나갔어요.
bi-ga wa-seo bakk-e an na-gass-eo-yo., bi ga wa seo bakk e an na gass eo yo.
Using 안 implies intentional refusal, which conflicts with the situational cause.
Which negation to use when inability causes not doing something?
Which negation is appropriate for intentional refusal?
Fill in the blank: 'I ___ exercised yesterday.'
Which negation fits: 'Because it rained, I ___ went outside.'
What does it mean?
