Should not

This pattern is used to express prohibition, forbid an action, or give strong advice against doing something. It translates to "you shouldn't," "you must not," or "you can't."

Meaning & Usage

It literally means "if you do [verb], it is not okay/it won't do." It's formed by combining the conditional -(으)면 (if/when) with 안 되다 (to not be okay).

Formation

Verb stems ending in a vowel or ㄹ: Attach -면 안 되다.

가다 (to go) → 가면 안 되다

울다 (to cry) → 울면 안 되다

열다 (to open) → 열면 안 되다

Verb stems ending in a consonant (except ㄹ): Attach -으면 안 되다.

먹다 (to eat) → 먹으면 안 되다

찍다 (to take a picture) → 찍으면 안 되다

웃다 (to laugh) → 웃으면 안 되다

여기서 자면 안 돼. / 사진 찍으면 안 돼. / 먹으면 안 돼. / 열면 안 돼.

Both patterns express prohibition, but they have different nuances. Choosing the right one makes your Korean sound more natural.

-(으)면 안 되다 (Stating a Rule/Consequence)

This pattern explains that an action is not allowed or advisable. It focuses on the general rule or the negative consequence. It can feel a bit softer and more explanatory than a direct command.

Context: Explaining why something is a bad idea or what the rules are.

여기서 떠들면 안 돼요. (It's not okay to be loud here.)

-지 마세요 / -지 마 (Direct Command)

This is a direct imperative telling the listener not to do something. It's a command focused on stopping the listener's action.

Context: Directly telling someone to stop or not to start an action.

떠들지 마세요. (Don't be loud.)

In many cases, they are interchangeable, but -(으)면 안 되다 often sounds like you're stating a fact, while -지 마세요 is a direct order.

여기서 담배 피우면 안 돼요. / 담배 피우지 마세요. / 비밀번호 알려주면 안 돼. / 비밀번호 알려주지 마.