NEGATIVE FORM

There are three ways to make verbs into their negative forms, and they all have diverse usage.

FIRST WAY

All you need to do is removing -다 from the infinitive verb and putting the -지 particle. Then, you'll need to add the verb 않다 conjugated however you want to let the interlocutor get the verbal tense.

Eg: to dance, 춤추다

I don't dance → 나는 춤추지 않아요.

I didn't dance → 나는 춤추지 않았어요.

SECOND WAY

You only need to put 안 before the verb (conjugated as you need).

Eg: 자다 (to sleep) → 자요.

I don't want to sleep → 안 자요.

THIRD WAY

You only need to put 못 before the verb (conjugated as you need).

Eg: 자다 (to sleep) → 자요.

I can't sleep → 못 자요.

PAY ATTENTION to the small differences, because the second way is intentional but the third refers to an impossibility of doing something. Imagine if you received an invitation and you said "안 와요" instead of "못 와요": so offensive!

REMEMBER THAT apart from the ways to make verbs into their negative form, sometimes in Korean, there's just the negative version of a verb.

For example, the verb 모르다 (not to know) is the opposite of 알다 (to know), so you shouldn't say "알지 않아요" to intend that you don't know something, you'll only need to conjugate 모르다 (몰라요).

The same will happen with the verb 싫어하다 (not to like), so you won't say "좋아하지 않아요", but you'll do say "싫어해요".