Prohibition: -지 마(세요) — 'Don't'

To tell someone not to do something, English simply negates the command: "Go" becomes "Don't go." Korean does something structurally different and, once you see it, cleaner. It does not negate the imperative ending; it swaps in a whole auxiliary verb, 말다 ("to desist, to leave off"), and puts the main verb in front of it with -지. The result is -지 말다 — literally "desist from doing X." This is the single construction behind every Korean prohibition, from a mother's 울지 마 to a park sign's 들어가지 마십시오.

The core pattern: stem + -지 말다

Attach -지 to the main verb stem, then conjugate the auxiliary 말다 for register:

Notice that only the auxiliary changes across registers — the main verb stays frozen as [stem]-지. Whether you are being intimate, polite, or formal, it is always 가지, 걱정하지, 울지 in front; 말다 does all the register work behind it.

Why it's 마세요 and not ✗말세요: the ㄹ drops

말다 ends its stem in ㄹ, which makes it a textbook ㄹ-stem. Recall the rule: a ㄹ-stem loses its ㄹ before endings beginning in ㄴ, ㅂ, ㅅ, and before the -(으) forms. The polite ending -(으)세요 and the formal -(으)십시오 both begin their consonant with ㅅ — a trigger — so the ㄹ of 말다 elides:

• 말 + (으)세요 → ㄹ drops, no 으 inserted → 마세요
• 말 + (으)십시오 → 마십시오

This is why both ✗말으세요 (wrongly inserting the 으 buffer — ㄹ-stems never take 으) and ✗말세요 (wrongly keeping the ㄹ before ㅅ) are impossible. The correct form has neither the ㄹ nor the 으: 마세요.

The intimate imperative of 말다 is likewise 마 (or the blunter 마라), with the ㄹ dropped — 하지 마 / 하지 마라, never ✗하지 말아... though you will hear the fuller 말아라 in careful or older speech; both 마라 and 말아라 are now accepted.

-지 말고: "don't… — instead…"

The auxiliary 말다 can also take the connective -고, giving -지 말고 "don't do X (but rather)." It sets up a contrast: reject one action, propose another in the same breath. Here the ㄹ of 말다 stays, because -고 begins with ㄱ, which is not a trigger — so it is 말고, not ✗마고. That contrast (마세요 with ㄹ dropped, but 말고 with ㄹ kept) is a perfect miniature of the whole ㄹ-stem rule.

The big reframing: prohibition is NOT 안 + imperative

This is the error English hardwires. In English "don't go" is transparently "do" + "not" + "go" — you negate the verb and keep the command. So learners reach for Korean's ordinary negator 안 and produce ✗안 가세요, expecting "don't go." It does not mean that. 안 negates statements ("안 가요" = "I'm not going"), and ✗안 가세요 lands as an ill-formed or bizarre "you (honorably) don't go / aren't you going?" — never as a prohibition. To forbid an action you must use the dedicated -지 말다; there is no shortcut through 안.

A note on descriptive verbs

Prohibition is fundamentally an action-verb pattern. You forbid doing, not being. So while 뛰지 마세요 ("don't run") is natural, forbidding a state — ✗예쁘지 마세요 ("don't be pretty") — is nonsensical, because the addressee cannot choose to stop being in that state on command. When a "don't be X" meaning is genuinely intended, Korean recasts it as an action: 슬퍼하지 마세요 "don't grieve / don't be sad" uses the action verb 슬퍼하다 ("to feel/act sad"), not the adjective 슬프다. The -지 말다 slot wants something the listener can actually stop doing.

Don't confuse it with -고 말다 ("end up doing")

The verb 말다 leads a double life, and it is worth flagging so you are not thrown when you meet its other job. Alongside the prohibitive -지 말다 ("desist from"), there is an aspectual auxiliary -고 말다 meaning "to end up doing (something), often regrettably" — a completely different construction that happens to reuse the same verb. In -고 말다, the ㄹ behaves normally (it is before -았-, a vowel-initial ending, so it stays and liaises).

The two never actually collide in practice — one takes -지 and forbids, the other takes -고 and reports an outcome — but seeing 말다 in a sentence that clearly is not a prohibition (울고 말았어요 is a statement about the past, not a command) is a useful reminder that the word itself is not inherently "don't." The prohibitive force lives in the -지 … 마세요 frame as a whole, not in 말다 alone.

Common Mistakes

1. Using 안 + imperative to mean "don't." Prohibition needs -지 말다.

2. Inserting the 으 buffer into 말다. ㄹ-stems never take 으.

3. Keeping the ㄹ before -세요. ㅅ is a trigger, so the ㄹ must drop.

4. Using intimate -지 마 with someone you owe politeness. The construction is right; the register is too low.

5. Dropping the ㄹ before -고. In -지 말고 the ㄹ stays.

Key Takeaways

• Korean "don't" = verb stem + -지 말다, not a negated imperative. The main verb freezes as -지; the auxiliary 말다 carries the register.
• Registers: polite -지 마세요, intimate -지 마(라), formal -지 마십시오.
• 말다 is a ㄹ-stem: the ㄹ drops before -세요/-십시오 (→ 마세요, never ✗말으세요 / ✗말세요) but stays before -고 (→ 말고).
• -지 말고 = "don't do X — instead…" (늦지 말고 일찍 오세요).
• Prohibition is not 안 + imperative; ✗안 가세요 does not mean "don't go." It is an action-verb pattern (recast states with an action verb: 슬퍼하지 마세요).