안 vs 못 (an vs mot): "don't" vs "can't" in Korean

Your coworker asks: "Are you coming to the team dinner tonight?" You can answer with 안 or 못. Both words are short, and both go in the same place. But one sounds like "Sorry, I can't come." The other sounds like "No, I won't."

What is the difference?

• 안 — "don't / won't." It is your choice, or just a fact.
• 못 — "can't." Something stops you: no time, no skill, or no permission.

Both words go just before the verb. They do not go at the start of the sentence.

• 저는 고기를 안 먹어요. — "I don't eat meat."
• 오늘은 못 만나요. — "I can't meet today."

Saying no without hurting anyone

Here, 안 and 못 are not only grammar. They are also about being kind to people. Let's go back to the team dinner.

• Not good: 안 가요. It sounds like your own decision. The people who invited you may feel rejected.
• Good: 죄송해요, 오늘은 못 가요. [죄송해요, 오느른 몯 까요.] (joesonghaeyo, oneureun mot gayo) — "Sorry, I can't come today." It shows that something outside your control stops you.
• Good: 저는 매운 거 잘 못 먹어요. [저는 매운 거 잘 몬 머거요.] (jeoneun maeun geo jal mot meogeoyo) — "I can't eat spicy food very well."

The last sentence uses 잘 (jal) — "well". It is a soft way to say no to a dish. You do not say you dislike the food. You only say spicy food is hard for you.

When you say no to a person, use 못. Koreans do this even when the real reason is "I want to stay home."

Where do they go with 하다 verbs?

Many Korean verbs are a noun + 하다 (hada) — "to do". For example: 공부하다 (study), 운동하다 (exercise), 전화하다 (call). With these verbs, put 안 or 못 between the noun and 하다.

You make the 하다 part negative, not the noun.

A space can change the meaning here. With no space, 못하다 means "to be bad at something". So 노래를 못해요 [노래를 모태요] (noraereul motaeyo) means "I'm bad at singing." With a space, 못 해요 means "I can't do it (now)."

Easy mistakes

• 안 있어요 is wrong. For "there isn't" or "I don't have", Korean has its own word: 없어요 [업써요] (eopseoyo).
• 안 알아요 is wrong. "I don't know" is 몰라요 (mollayo).
• 못 비싸요 is wrong. 못 works with action verbs, not with describing words like "expensive". Use 안: 안 비싸요 ("It's not expensive"), 안 매워요 ("It's not spicy").
• 안 공부해요 is wrong. Split the 하다 verb: 공부 안 해요.

What are the long forms?

Each negative has a second, longer form. You add an ending to the verb stem (the verb without its ending).

The meaning is the same. The long forms sound more careful. You will see them in writing, on the news and in formal speech. In daily talk, people use the short forms more.

Why does 못 sound kinder?

In Korean, a direct "I won't" can make the other person feel uncomfortable. 못 takes the reason away from you. The message is: "I want to come, but I can't."

After 못 가요, nobody expects a long list of reasons. The word itself already says "I would like to, but…". So 못 is the normal choice for a polite no.

You will also hear 안 돼요 (an dwaeyo) very often. It means "No, that is not allowed" or "That won't work." Shop staff, parents and many others use it to refuse a request. For example: 여기서 사진 찍으면 안 돼요 — "You can't take photos here."

Quick check

1. "I don't exercise." 운동___ → 운동 안 해요
2. You say no to an invitation politely: 내일은 ___ 가요. → 못
3. "I don't know." → not 안 알아요, but 몰라요