We have talked a lot about demands, approval and necessity, but, of course, there are also things such as prohibitions. We sometimes want to say that you simply cannot do something. -(으)면 안 되다 is the Korean grammar pattern you can use to tell that to someone. It is one of two negatives of the expression -아/어야 되다/하다.
Not Allowed -(으)면 안 되다
The Korean grammar expression -(으)면 안 되다 all in all is not that complicated to understand. When you use it, you are informing someone that a particular action or behaviour is not allowed. If you translate a sentence with this pattern, this part you would translate as “may not” or “not allowed to”. Let’s look at an example:
Example: 실내에서 담배를 피우면 안 돼요.
Translation: Smoking indoors is not allowed.
-(으)면 안 되다 is particularly useful to inform others of social conventions or norms. So expect to see it quite often on signs to inform that smoking is not allowed indoors.
How To Use
The rules on how to use -(으)면 안 되다 are not overly complicated. You simply need to get used to them. First you need to know this expression is used by both verbs and adjectives. Secondly, for this type of conjugation you need to take a look at the presence or absence of a batchim (final consonant). The rules are as following:
- If the verb stem ends in a vowel or ㄹ the ending you use, is -면 안 되다.
- If the verb stem ends in a consonant other than a ㄹ, you use the ending -으면 안 되다.
After you’ve done that, the only thing that is left for you to do, is conjugating the verb 되다. As a side note, you need to keep irregular verbs in mind for this type of conjugation. The most confusing irregular verb types are the ㅅ irregular verbs and the ㄷ irregular verbs.
There is one important aspect of this pattern I need to tell you. This is one of the Korean grammar patterns for which a double negative is used. This double negative is -지 않으면 안 돼다. The double negative is used to emphasize the absolute necessity for an action or behaviour. It is thus an emphasized version of the expression -아/어야 되다/하다. Let’s take a look at an example of this:
Example: 다음 주에 중요한 시험이 있어서 공부하지 않으면 안 돼요 (=공부해야 해요)
Translation: Because I have an important test next week, I must study.