Grammar
-(으)면 안 되다
say an action must not be done
Form
Verb stem + -(으)면 안 되다 — “must not”, “should not”.
Function
Presents an action as forbidden or inappropriate; the negative evaluation concerns whether the action may be done.
Why this form?
-지 말다 — “do not…”: a direct prohibition or request, whereas -(으)면 안 되다 presents an action as not allowed.
-아/어서는 안 되다 — “must not”: often a stronger or more rule-like prohibition.
Useful conjugations
하다 → 하면 안 되다; 가다 → 가면 안 되다. 안 될 is the prospective modifier of 안 되다 before a dependent noun such as 것.
Forms not to confuse
- -지 말다
여기서 뛰지 마세요. — Don’t run here.
- -아/어서는 안 되다
규칙을 어겨서는 안 돼요. — You must not break the rules.
Examples
그런데 확인하러 가면 안 될 것 같아요. — But I don’t think we should go check.
지금 들어가면 안 돼요. — You must not go in now.