Negation & Prohibition
Express negation with 안/못 and prohibition with -지 마세요. Understand the difference between inability and refusal.
Building on the basic negation from Lesson 3-4, this lesson covers prohibition (telling someone NOT to do something) and the nuanced distinction between 안 (won't / don't) and 못 (can't). For prohibition, the formula is verb stem + -지 마세요 (please don't) or -지 마요 (more casual). 들어가지 마세요 (please don't enter), 하지 마요 (don't do it).
The distinction between 안 and 못 carries social weight. 안 implies choice (I'm not eating this because I don't want to). 못 implies inability (I can't eat this because of allergies / physical limitation). Using 못 when you meant 안 can imply you wanted to do something but couldn't, which may invite questions or unwanted help. Using 안 when you meant 못 can sound dismissive. Pay attention to whether refusal is voluntary or not when choosing between them.
안 vs. 못 — Negation
안 (voluntary negation): placed before a verb to express 'don't / won't'. Shows choice or unwillingness. 못 (inability): placed before a verb to express 'can't'. Shows inability due to skill, circumstance, or external reasons. 하다 verbs: 안 해요 / 못 해요 (not 안 하다요).
-지 마세요 / -지 마 — Don't (prohibition)
Attach -지 마세요 to the verb stem to tell someone not to do something (polite). Use -지 마 for casual speech. Stronger version: -지 마십시오 (formal). Common in signs, instructions, and warnings.
How It Works
This lesson revisits 안 and 못 from Level 3 and adds prohibition, which is a genuinely different operation.
안 and 못 negate a statement: you do not do something, or you cannot. -지 말다 does something else — it tells someone not to do it. The three cover statement-negation, ability-negation and prohibition respectively, and they are not interchangeable.
-지 마세요 attaches directly to the verb stem with no vowel rule: 가지 마세요, 먹지 마세요, 하지 마세요. The casual form drops to -지 마 and the formal form rises to -지 마십시오, which is what you see on official signage.
The underlying verb is 말다, which means roughly 'to desist'. Knowing this explains the shape: 마세요 is 말다 conjugated with the honorific ending, with the ㄹ dropping before ㅅ as it regularly does in Korean.
One structural point worth noting: because -지 말다 is a command form, it cannot be preceded by -아/어서 for the same reason covered in Lesson 5-2. If you want to give a reason for telling someone not to do something, you must use -(으)니까: 위험하니까 만지지 마세요.
That connection between lessons is not a coincidence — the imperative restriction applies to every command form in the language.
Where You'll Hear It
-지 마세요 is everywhere in public space. 들어가지 마세요 ('do not enter'), 만지지 마세요 ('do not touch'), 뛰지 마세요 ('do not run') appear on signs throughout Korea, usually in the formal -지 마십시오 form in official contexts.
In conversation the casual -지 마 is what friends use with each other: 걱정하지 마 ('don't worry') is one of the most common things you will hear in a supportive context, and 신경 쓰지 마 ('don't mind it') is equally frequent.
걱정하지 마세요 is worth having ready as a set phrase because it is a genuinely useful thing to say and it comes up whenever someone apologises for an inconvenience.
The 안 / 못 distinction continues to carry real meaning here. 술 안 마셔요 says you choose not to drink; 술 못 마셔요 says you cannot. In Korean drinking culture, where declining is socially delicate, this distinction matters — 못 마셔요 is generally accepted without further pressure, while 안 마셔요 may invite persuasion.
For 하다 verbs, remember the split from Level 3: 운전 안 해요 and 운전 못 해요, with the negation inside the compound.
Cultural & Language Note
지 마세요 is the standard prohibition and appears constantly on public signage, but in conversation Koreans often soften it further with 지 마시고 followed by an alternative. Direct prohibition to someone older or of higher status is generally avoided altogether in favour of indirect phrasing, so the grammar you learn here is used more downward and laterally than upward.
Common Mistakes to Avoid
안 negates choice while 못 negates ability, and this carries into prohibition: 못 가요 means you are unable, 안 가요 means you decline. Learners also attach 지 마세요 to adjectives, but prohibition applies only to actions — 예쁘지 마세요 is meaningless.
How to Practice This Lesson
Separate the three operations by what they do, not by how they look. Write three sentences about the same verb: 안 가요 (I don't go), 못 가요 (I can't go), 가지 마세요 (don't go). Seeing them together makes clear that only the third is addressed to someone else.
Drill -지 마세요 with the five prohibitions you are most likely to see on signs, since recognition is the primary use for most learners: 들어가지, 만지지, 뛰지, 사진 찍지, 먹지.
Practise the -(으)니까 requirement explicitly, because it is the kind of rule that only surfaces when you try to build a real sentence. Write three prohibitions with reasons attached and confirm that none of them uses -아/어서.
For drinking situations specifically, decide in advance which form you will use and practise it, because that is not a sentence you want to be constructing under social pressure.