절대 뒤돌아보면 안 돼

The line, explained

The old woman grips your wrist at the mouth of the tunnel. 절대 뒤돌아보면 안 돼. 'You must never look back.' Every horror fan knows what happens next. This line uses the Korean pattern for a firm prohibition, -(으)면 안 돼, 'you must not'. It is direct, serious and very common, both in scary films and in everyday rules, from signs in museums to parents at the dinner table.

절대 means 'absolutely', and with a negative it means 'never'. It is the word that turns a warning into a commandment: 절대 안 돼, absolutely not. 뒤돌아보면 comes from 뒤돌아보다, to turn around and look back. It is built from 뒤 (back, behind), 돌다 (to turn) and 보다 (to look). The stem 뒤돌아보 ends in a vowel, so it takes -면, meaning 'if': 'if you look back'.

안 돼 finishes the thought: 'it's not okay', 'it won't do'. 돼 is from 되다, to work out or be allowed, and 안 makes it negative. Put the two halves together and you get 'if you look back, it is not okay', which is Korean's way of saying 'you must not'. The rule for -(으)면 is simple: vowel stems and ㄹ stems take -면 (보면, 열면), and other consonant stems take -으면 (먹으면, 찍으면).

This pattern is the mirror image of -아/어도 돼, 'it's okay to'. Ask 봐도 돼? (can I look?) and the answer might be 보면 안 돼 (you can't look). To be polite, add 요: 사진 찍으면 안 돼요, you can't take photos. The softer 'don't' from -지 마 is a direct request between people, while -(으)면 안 돼 sounds more like a rule, something true no matter who you are.

Whisper it the way the film would: jeol-dae, a pause, then dwi-do-ra-bo-myeon an dwae. Then change the rule: 절대 문 열면 안 돼, you must never open the door; 절대 소리 내면 안 돼, you must never make a sound; 절대 잠들면 안 돼, you must never fall asleep. Each one could be the tagline of a different film. Just remember: in horror, someone always breaks the rule.