-지 마세요 is the negative of -(으)세요. It is the Korean imperative to demand or request someone to not do something. It is important to know as it is common.
Expressing an impossibility for something to happen or your inability to do something, can be done with using the negation -지 못하다 or simply 못 in Korean.
-지 않다, and its short-form 안, are the Korean equivalent to the English ‘not’. It is a rather simple way to express negation in Korean.
In Korean, certain times you have to use specific words to negate something. There are three cases of word negation: 아니다, 없다 and 모르다.