Korean Negation with 안 and 못

In Brief

Put 안 before a verb when an action does not happen or you choose not to do it: 안 가요 (“I don’t/won’t go”). Use 못 when inability or circumstances prevent it: 못 가요 (“I can’t go”). Their longer counterparts are -지 않다 and -지 못하다; for “there is no…” or “I don’t have…,” use 없다.

Overview

Negation turns a positive statement into a negative one. Korean has no single word that matches every English use of not, don’t, and can’t. Instead, the form you choose often tells the listener whether something simply does not happen, whether you refuse or choose not to do it, or whether you are unable to do it.

At A1, the most useful contrast is 안 versus 못. Both normally come immediately before the verb or descriptive verb (a Korean word that describes a state but behaves grammatically like a verb). Compare 오늘 안 가요 (“I’m not going today”) with 오늘 못 가요 (“I can’t go today”). The first reports or chooses non-action; the second points to inability or an obstacle.

Korean subjects are often left unspoken when the context makes them clear. Consequently, 안 가요 can mean “I don’t go,” “I’m not going,” “he isn’t going,” or “we won’t go,” depending on the conversation. The negation does not determine the subject or the English tense; context does much of that work.

How It Works

The beginner rule: 안 for “not,” 못 for “cannot”

Meaning	Short form	Basic pattern	Example	Natural English
not do / do not choose to do	안	안 + verb	안 먹어요.	I don’t eat it. / I won’t eat it.
be unable to do	못	못 + verb	못 먹어요.	I can’t eat it.
not be a certain way	안	안 + descriptive verb	안 비싸요.	It isn’t expensive.

안 is an adverb: a word that modifies the action or state. It stays unchanged. The main verb still carries the polite ending, tense, or other grammar:

• 가요 → 안 가요: go → do not go
• 갔어요 → 안 갔어요: went → did not go
• 바빠요 → 안 바빠요: am busy → am not busy
• 먹을 거예요 → 안 먹을 거예요: will eat → will not eat

못 also stays unchanged. It is mainly used with actions that can succeed or fail:

• 가요 → 못 가요: go → cannot go
• 잤어요 → 못 잤어요: slept → could not sleep
• 만나요 → 못 만나요: meet → cannot meet

English won’t is ambiguous. It can indicate a future fact, a decision, or refusal. Korean 안 갈 거예요 normally means “I’m not going / I won’t go,” whereas 못 갈 거예요 means “I won’t be able to go.” Do not automatically translate every English won’t with 못.

Placement with 하다 verbs

Many Korean verbs consist of a noun plus 하다 (“do”), such as 공부하다 (“study”), 운동하다 (“exercise”), and 요리하다 (“cook”). In the common short negative form, place 안 or 못 directly before 하다, separating the noun:

Positive	Negative with 안	Inability with 못
공부해요.	공부 안 해요.	공부 못 해요.
운동해요.	운동 안 해요.	운동 못 해요.
요리해요.	요리 안 해요.	요리 못 해요.

This is why 안 공부해요 is not the normal beginner pattern. Treat 공부 + 하다 as “study-do” and negate the 하다 part.

Not every verb ending in 하다 is felt as a freely separable noun-plus-하다 expression in exactly the same way. If unsure, the long form described below is reliable: 공부하지 않아요.

Long forms: -지 않다 and -지 못하다

The long forms attach -지 to the verb stem (the verb without dictionary -다) and add 않다 or 못하다. In everyday polite speech, these become 않아요 and 못해요.

Dictionary form	Stem	“do not”	“cannot”
가다 (to go)	가-	가지 않아요	가지 못해요
먹다 (to eat)	먹-	먹지 않아요	먹지 못해요
공부하다 (to study)	공부하-	공부하지 않아요	공부하지 못해요
바쁘다 (to be busy)	바쁘-	바쁘지 않아요	—

The core meanings normally match the short forms:

• 안 가요 ≈ 가지 않아요: do not go
• 못 가요 ≈ 가지 못해요: cannot go

The long form often sounds more deliberate, emphatic, or suitable for careful and formal writing, but it is also completely normal in speech. It is especially convenient with long verbs because the scope of negation is clear.

With ordinary descriptive verbs, use 안 or -지 않다: 춥지 않아요 (“It isn’t cold”). 못 is not a general substitute for “not” and usually sounds wrong when no ability or achievable result is involved.

없다: nonexistence and not having

Korean usually does not negate 있다 (“to exist; to have”) by saying 안 있어요. It uses the separate negative word 없다:

Positive	Negative	Meaning
시간이 있어요.	시간이 없어요.	I have time. / I don’t have time.
사람이 있어요.	사람이 없어요.	There is someone. / There is no one.
책이 있어요.	책이 없어요.	I have a book. / I don’t have a book.

The noun commonly takes 이/가, a subject marker (a small particle showing what exists or is absent). English changes between “there isn’t” and “don’t have,” but Korean can use the same 없어요 pattern for both.

아니다: “is not” before a noun

When you mean that someone or something is not a noun, use 아니다, not 안 plus 이다:

• 학생이에요. — (They) are a student.
• 학생이 아니에요. — (They) are not a student.

The noun before 아니다 is usually marked with 이/가: 학생이 아니에요, 의사가 아니에요. This pattern is different from negating an action with 안.

Examples in Context

Korean	English	Note
오늘은 회사에 안 가요.	I’m not going to work today.	안: the action will not happen
커피를 안 마셔요.	I don’t drink coffee.	A habit or choice
어제 숙제를 안 했어요.	I didn’t do the homework yesterday.	안 comes before 했어요
이 가방은 안 비싸요.	This bag isn’t expensive.	안 with a descriptive verb
매운 음식을 못 먹어요.	I can’t eat spicy food.	Inability, possibly physical tolerance
일이 많아서 오늘 못 만나요.	I can’t meet you today because I have a lot of work.	An outside circumstance prevents it
너무 시끄러워서 못 잤어요.	It was so noisy that I couldn’t sleep.	Past inability
아직 한국어를 잘 못해요.	I still can’t speak Korean well.	Limited ability
주말에는 일하지 않아요.	I don’t work on weekends.	Long neutral negative
비가 와서 출발하지 못했어요.	We couldn’t leave because it rained.	Long inability form
냉장고에 우유가 없어요.	There is no milk in the refrigerator.	없다: nonexistence
지금 시간이 없어요.	I don’t have time now.	없다: lack or possession
저는 의사가 아니에요.	I’m not a doctor.	아니다 negates noun identity
다음 주에는 안 갈 거예요.	I’m not going next week.	Intention or future non-action
다음 주에는 못 갈 거예요.	I won’t be able to go next week.	Predicted inability

The pair in the final two rows is worth memorizing. The event is the same—going next week—but 안 presents non-participation, while 못 presents an obstacle or lack of ability.

Common Mistakes

Using 안 when you mean “unable”

• Wrong for the intended meaning: 아파서 학교에 안 갔어요. (“I was sick, so I didn’t go to school.”)
• Better: 아파서 학교에 못 갔어요. (“I was sick, so I couldn’t go to school.”)
• Why: 안 갔어요 only says that you did not go and can sound like a choice. 못 갔어요 clearly connects the illness with inability to go.

Treating 못 as a general word for “not”

• Wrong: 날씨가 못 추워요.
• Right: 날씨가 안 추워요. / 날씨가 춥지 않아요.
• Why: Coldness is a state here, not an action someone fails to perform. Use 안 or -지 않다 for a plain negative state.

Putting 안 before the noun in a 하다 verb

• Awkward as a basic pattern: 안 공부해요.
• Natural: 공부 안 해요. / 공부하지 않아요.
• Why: In common noun-plus-하다 verbs, short negation goes immediately before 하다.

Negating 있다 mechanically

• Wrong for ordinary “there isn’t / I don’t have”: 시간이 안 있어요.
• Right: 시간이 없어요.
• Why: 없다 is the standard opposite of 있다. 안 있다 can occur only in special contrasts or constructions and should not be your default.

Saying 안 이에요 for “is not a noun”

• Wrong: 학생 안 이에요.
• Right: 학생이 아니에요.
• Why: Noun identity uses 이다 in the positive and 아니다 in the negative. It does not follow the ordinary 안 + verb pattern.

Reading every subject into the sentence

• Mistake: Assuming 안 가요 always means “I don’t go.”
• Better: Use the conversation to identify who is not going.
• Why: Korean regularly omits subjects. English translations must add one, but the Korean sentence itself may not specify it.

Usage Notes

Choice, intention, and social tact

The difference between 안 and 못 can affect how your reason sounds. 오늘 안 가요 may suggest “I have decided not to go.” 오늘 못 가요 suggests “I cannot go because something prevents me.” In invitations and apologies, 못 가요 can therefore sound less blunt when inability is genuinely the reason. Do not use it merely to avoid responsibility if you simply do not want to go; the forms still convey different meanings.

안 does not always imply a conscious refusal. In 요즘 비가 안 와요 (“It isn’t raining these days”), rain makes no choice. The broad meaning is simply that the event does not occur. “Choice” is a useful beginner contrast for actions by people, not an absolute definition.

잘 못 versus 잘못

Spacing matters:

• 잘 못해요: cannot do it well / am not good at it
• 잘못해요: do it wrongly; make a mistake

For example, 한국어를 잘 못해요 means “I’m not good at Korean.” 제가 잘못했어요 means “I was wrong” or “It was my fault.” Learners often hear these as nearly identical, so learn them as separate chunks.

Short and long forms

Short 안/못 forms are extremely common in conversation. -지 않다/-지 못하다 can sound more explicit and are frequent in writing, presentations, news, and careful explanations. This is a tendency rather than a strict formal-versus-informal division: both types can take polite, casual, or formal endings.

Beyond the Basics

You do not need to master the following points at A1, but they explain forms you will encounter later.

Negation and tense attach to the final verb

In a long negative construction, tense is normally shown on 않다 or 못하다, the final verb:

• 가지 않았어요 — did not go
• 가지 못했어요 — could not go
• 가지 않을 거예요 — will not go

The short forms instead precede the already conjugated main verb: 안 갔어요, 못 갔어요. Avoid forms such as 갔지 않아요 when your intended beginner meaning is simply “did not go”; 가지 않았어요 is the standard pattern.

못하다 can describe poor skill

With activities, 못하다 may mean either “cannot do” or “be bad at doing,” depending on context:

• 저는 수영을 못해요. — I can’t swim / I’m bad at swimming.
• 오늘은 다쳐서 수영을 못해요. — I can’t swim today because I’m injured.

The second sentence clearly describes a temporary obstacle. Adding 잘 produces 잘 못해요, often “I can’t do it well” or “I’m not good at it.”

Negative questions depend heavily on context

A question such as 안 가요? can mean “Aren’t you going?” or, with an inviting tone, “Won’t you go?” A simple 네 or 아니요 can be confusing across languages because Korean responses often follow whether the speaker accepts or rejects the statement in the question. At beginner level, answer with a full phrase—네, 안 가요 (“Right, I’m not going”) or 아니요, 가요 (“No, I am going”)—to remove ambiguity.

Stronger and double negation

More advanced Korean combines negation with expressions such as 수 없다 (“there is no way/capacity to”) or uses double negation for emphasis. 가지 않을 수 없어요 literally has the shape “cannot not go” and means “I have no choice but to go.” This is not the same as the A1 form 가지 못해요 (“I cannot go”): in fact, the practical conclusions are opposite. Study this only after the basic 안/못 contrast is automatic.

Practice Tips

1. Make contrast pairs. Choose five everyday verbs and say both versions: 안 먹어요 / 못 먹어요, 안 가요 / 못 가요. Invent one realistic reason for each so the meaning, not just the word order, becomes memorable.
2. Transform all four ways. Start with 가요, then produce 안 가요, 못 가요, 가지 않아요, and 가지 못해요. Repeat in the past with 갔어요.
3. Sort English prompts by meaning. Before translating “don’t,” “won’t,” or “can’t,” ask: Is this non-action, a decision, inability, nonexistence, or “is not a noun”? Then choose 안, 못, 없다, or 아니다.

Related Concepts

• Prerequisite: Polite Ending -아/어요 — supplies the everyday polite endings in 가요, 않아요, 못해요, and 없어요.
• Later extension: Double Negation -지 않을 수 없다 — uses negation twice to express inevitability or strong affirmation.