We already discussed the form -(으)세요, which is the basic way to politely asking someone to do something, give directions and the likes: an imperative in Korean. However, you cannot use it to ask someone to not do something. To ask the opposite you need to use a different pattern and that pattern is -지 마세요.
The form -지 마세요 is the negative, polite imperative in Korean. It is thus the opposite of the form -(으)세요 in that regard. You can use it to order someone not do something or request them that. It is a highly flexible pattern that is used often in Korean and thus it is very important to know early on. This is especially true if you plan to live in Korea.
가: 내일 병원에 갈 거예요.
나: 그럼 오늘 술을 마시지 마세요.
A: Tomorrow I’m going to the hospital.
B: Then don’t drink today.
How To Use
Using the form -지 마세요 is incredibly easy as you really do not have to take care of a lot of things. First, you simply need the verb stem and simply attach -지 마세요 to it since it follows the ‘no rule’ pattern. After that, you are done conjugating.
However, keep in mind that you cannot use this pattern with adjectives or 이다. If you need to use it with an adjective, you will have to first turn it into a verb using the pattern -아/어지다. Furthermore, unlike -(으)세요, which has some adjectives that use it idiomatically, such adjectives don’t really exist for -지 마세요. Keep this in mind. Lastly, you’ll often encounter this expression in its formal form in public. Therefore, it is important to memorize that form as well which is -지 마십시오.