안 V/A

Let’s start with the easiest way to conjugate a verb to a negative form.

You just need to place a “안” particle before the verb (or adjective). Just like in english you would place a “not” or a “don’t” like in the sentences “I don't go to school on sunday” or “This meal is not delicious”, in Korean you would say:

• 일요일에 학교에 안 가요
  I don’t go to shcool on sunday
• 커피를 안 마셔요
  I don’t drink coffee
• 이 밥은 안 매워요
  This meal is not spicy
• 그 옷은 안 비싸요
  This piece of clothing is not cheap

With verbs in 하다, since they can also be said as N를 하다 (ex: 공부를 하다) you can also change them to a negative form like this:

• 공부를 안 해요
  I don’t study
• 운동을 안 해요
  I don’t exercice

못 V

Another way to do is to put the particle “못” in front of a verb. However 못 has a completely different meaning: it express the inability or incapacity of doing something.

It’s more similar to the word “cannot” in english. For example:

• 다음주 토요일에 결혼식에 못 가요
  I cannot go to the wedding on next week Saturday
• 그 사람은 못 믿어요
  I can’t believe that person
• 못 자요
  I cannot sleep
• 저는 수영을 못 해요.
  I can't swim

V/A지 않다, V/A지 못하다

It is also possible to make a negative sentence by using this pattern, which is also very common. Let’s see more examples:

• 아이들은 방을 정리하지 않아요
  The children don't tidy their room
• 그는 영화관에 자주 가지 않아요
  He doesn't go to the cinema often
• 매운 음식을 먹지 못해요
  I cannot eat spicy food
• 저는 수영하지 못합니다.
  I can't swim

With adjectives, using the pattern "-지 않다" in an interrogation can also be used to suggest an idea, even a positive one. This would refer to “isn’t that right?” or “isn’t it so?” in english.

• 이 영화는 좋지 않아요?
  This is good, isn't it?
• 밥은 맛있지 않아요?
  This is delicious, isn't it?
• 그가 우리 팀에 필요하지 않아요?
  Isn't he needed in our team?

Differences with “안” and “못” :

• Tone and Formality: "안 + verb" is straightforward and can be seen as a bit blunter or more direct. In contrast, "-지 않다" can soften the delivery slightly due to its formal structure.
• Contextual Preference: In quick and casual speech, "안" is frequently used for its brevity and ease of use. For professional settings, academic writing, or when a higher level of politeness is required, "-지 않다/못하다" is often the better choice. However "-지 않다/못하다" is also flexible and can be used in casual speech as well, especially when the speaker wants to emphasize the negation.