Korean negation: 안, 못, -지 않다, -지 못하다

안: don't, isn't

To make a verb negative, put (an) right before it: (meogeoyo), I eat → (an meogeoyo), I don't eat. It works the same with descriptive verbs: (an maewoyo), it isn't spicy; (an bissayo), it isn't expensive.

stays in front of the verb in every tense: (an gasseoyo), I didn't go; (an gal geoyeyo), I won't go. It often combines with (byeollo, not really) or (jeonhyeo, not at all).

저는 고기를 안 먹어요.Jeoneun gogireul an meogeoyo.I don't eat meat.
오늘은 안 추워요.Oneureun an chuwoyo.It isn't cold today.
커피 안 마셔요?Keopi an masyeoyo?Don't you drink coffee?
매운 음식은 별로 안 좋아해요.Maeun eumsigeun byeollo an joahaeyo.I don't really like spicy food.

하다 verbs: 안 goes before 하다

With verbs made of a noun + , such as (gongbuhada, to study), goes between the noun and : (gongbu an haeyo), I don't study. Saying 안 공부해요 is a common learner mistake.

This only works when the first part is a real noun you can “do”. (joahada, to like) and descriptive verbs such as (pigonhada, to be tired) take in front: (an joahaeyo), (an pigonhaeyo).

Verb	Negative	Not
(gongbuhada) to study	(gongbu an haeyo)	안 공부해요
(undonghada) to exercise	(undong an haeyo)	안 운동해요
(ilhada) to work	(il an haeyo)	안 일해요
(joahada) to like	(an joahaeyo)	좋아 안 해요
(pigonhada) to be tired	(an pigonhaeyo)	피곤 안 해요
(kkaekkeutada) to be clean	(an kkaekkeutaeyo)	깨끗 안 해요

주말에는 일 안 해요.Jumareneun il an haeyo.I don't work at weekends.
요즘 운동 안 해요.Yojeum undong an haeyo.I'm not exercising these days.

The long form: -지 않다

Instead of before the verb, you can add -지 않아요 to the stem: (meokji anayo), I don't eat; (gongbuhaji anayo), I don't study. The meaning is the same.

In everyday conversation the short is more common. The long form sounds a little more careful and is usual in writing and in the formal style: (meokji anseumnida). It is also the natural choice with long words and in questions such as (chupji anayo?), aren't you cold?

저는 술을 마시지 않아요.Jeoneun sureul masiji anayo.I don't drink alcohol.
춥지 않아요?Chupji anayo?Aren't you cold?
이 식당은 일요일에 문을 열지 않습니다.I sikdangeun iryoire muneul yeolji anseumnida.This restaurant is not open on Sundays.

못: can't

(mot) means “can't”: you'd like to, but something stops you. Compare (sureul an masyeoyo), I don't drink (my choice), with (sureul mot masyeoyo), I can't drink (for health, or because I'm driving). goes where goes, including between a noun and : (suyeong mot haeyo), I can't swim.

The long form is -지 못해요: (gaji motaeyo), more formal and common in writing. Written as one word, means “to be bad at”: (noraereul jal motaeyo), I'm not good at singing.

Meaning	Short	Long
don't, isn't	(an gayo)	(gaji anayo)
can't	(mot gayo)	(gaji motaeyo)
don't (noun + )	(gongbu an haeyo)	(gongbuhaji anayo)
can't (noun + )	(suyeong mot haeyo)	(suyeonghaji motaeyo)

오늘은 못 가요. 일이 있어요.Oneureun mot gayo. Iri isseoyo.I can't go today. I've got something on.
저는 매운 음식을 못 먹어요.Jeoneun maeun eumsigeul mot meogeoyo.I can't eat spicy food.
어제 잠을 못 잤어요.Eoje jameul mot jasseoyo.I couldn't sleep last night.

Nouns, 없다, 모르다 and “don't!”

A few negatives are separate words. For nouns, use (anieyo): (haksaengi anieyo), I'm not a student, never 안 학생이에요. “There isn't” and “don't have” are (eopseoyo), not 안 있어요. “Don't know” is (mollayo), from (moreuda), not 안 알아요.

To tell someone not to do something, add -지 마세요 to the stem: (geokjeonghaji maseyo), don't worry. And “nothing, nobody” are (amugeotdo) and (amudo), always with a negative verb.

Meaning	Use	Example
is not (noun)	(anieyo)	(haksaengi anieyo) I'm not a student.
there isn't, don't have	(eopseoyo)	(sigani eopseoyo) I don't have time.
don't know	(mollayo)	(jal moreugesseoyo) I'm not sure.
don't (do it)!	-지 마세요	(manjiji maseyo) Please don't touch.
nothing	(amugeotdo) + negative	(amugeotdo an meogeosseoyo) I haven't eaten anything.

걱정하지 마세요.Geokjeonghaji maseyo.Don't worry.
잘 모르겠어요.Jal moreugesseoyo.I'm not sure. / I don't really know.
여기에서 사진을 찍지 마세요.Yeogieseo sajineul jjikji maseyo.Please don't take photos here.