Learn Hardcore Korean: byeongwoneseoneun dambaereul piul su eobseoyo. - You can’t smoke cigarettes in the hospital.

-에서 marks the place where an action happens (here, the action of smoking).
Adding the topic marker -는/은 to get -에서는 makes that place the topic: “as for in hospitals…”. It often carries a contrastive nuance: in hospitals (as opposed to some other places).
Without the topic, 병원에서 담배를 피울 수 없어요 is a neutral statement. With 병원에서는, it subtly highlights hospitals as the contextual focus: “In hospitals, you can’t smoke.”

Example contrast: 병원에서는 담배를 피울 수 없어요. 밖에서는 괜찮아요. (In hospitals, you can’t smoke. Outside, it’s okay.)

Can I use 병원에 instead of 병원에서?

Generally, no. Use:

-에 for location of existence or destination: 병원에 사람이 많아요 (There are many people at the hospital).
-에서 for the place where an action occurs: 병원에서 기다려요 (I wait at the hospital).

Since smoking is an action, you need 병원에서 (and here, topicalized to 병원에서는).
Using 병원에 with an action verb like 피우다 is ungrammatical or unnatural.

What does 피울 수 없어요 literally mean?

피우- = smoke (verb stem)
-ㄹ = adnominal ending that turns the verb into a modifier before a noun (here, before 수)
수 = a bound noun meaning “way/means/possibility/ability”
없어요 = “there isn’t / one doesn’t have”

So it literally means “There isn’t a possibility/way to smoke,” i.e., “(You) can’t smoke.”
Note the required spacing: 피울 수 없어요 (not “피울수”).

Why is it 피울 and not 피우?

Before 수, Korean uses the adnominal form -ㄹ/을:

If the stem ends in a vowel: add -ㄹ → 피우- + ㄹ → 피울 수 (can smoke)
If the stem ends in a consonant: add -을 → 먹다 → 먹을 수

Other examples: 가다 → 갈 수 있다, 만나다 → 만날 수 있다.

What is the role of 를 in 담배를? Can it be dropped?

를/을 marks the direct object. 담배를 (피우다) = “to smoke a cigarette.”
In casual speech, the object marker is often dropped when the meaning is clear: 담배 피울 수 없어요.
In careful speech and writing, keep 를/을: 담배를 피울 수 없어요.

What’s the difference between 못 피워요, 피울 수 없어요, 피우면 안 돼요, and 피우지 마세요?

못 피워요: “I/you can’t smoke” (inability due to circumstance/skill/permission). Sounds a bit personal/situational.
피울 수 없어요: “It’s not possible/allowed to smoke.” Neutral and rule-like; polite.
피우면 안 돼요: “You must not smoke.” Stronger prohibition; normative.
피우지 마세요: “Please don’t smoke.” Polite prohibition/imperative.

For a posted rule, 피울 수 없습니다 or 피우면 안 됩니다 is common.

Is 담배 피다 okay, or must it be 담배를 피우다?

담배를 피우다 is the standard, neutral form (good for all contexts).
담배 피다 is very common in casual speech.
In careful writing or formal contexts, prefer 담배를 피우다. In conversation, you’ll hear both.

How do I pronounce the sentence? Any tricky parts?

Revised Romanization: Byeongwoneseoneun dambae-reul piul su eopseoyo.
Natural pronunciation notes:
- 없어요 is pronounced roughly like [업써요].
- You may hear the topicalized place contracted in speech: 병원에선 … (for 병원에서는).
A clear, slow reading: “byeong-won-e-seo-neun dam-bae-reul pi-ul su eop-sseo-yo.”

Who is the subject here? It’s not stated.

Korean often omits subjects when they’re obvious. Here the subject is generic: “people,” “you,” or “one.” So it means “(People/You) can’t smoke in the hospital.”

Does this mean all hospitals in general, or the specific hospital we’re in?

With the topic -에서는, it often reads as a general rule: “In hospitals (as a rule), you can’t smoke.” In context it can also mean “At the (this) hospital,” especially if previously mentioned. To make it specific, add a determiner: 이 병원에서는 담배를 피울 수 없어요 (“At this hospital…”).

How polite/formal is …없어요? What would a sign say?

…없어요 is polite informal (the standard -요 style you’d use with strangers).
A formal sign or announcement would use: …없습니다 or a set phrase like:
- 병원 내 흡연 금지 (No smoking in the hospital)
- 병원 내에서는 흡연을 할 수 없습니다 (Formal, explanatory)

How can I add emphasis, like “really can’t”?

담배를 피울 수가 없어요: adding 가 to 수 emphasizes impossibility.
담배를 피울 수는 없어요: contrastive; “You can’t smoke (at least), but…” (implying some contrasting allowance).
You can also add adverbs: 전혀/절대 피울 수 없어요 (absolutely not).

How do I say “You can smoke outside the hospital”?

병원 밖에서는 담배를 피울 수 있어요.
More generally: 밖에서는 담배를 피울 수 있어요.

Can I change the word order?

Yes, Korean allows flexible word order, though the default is most natural:

Default: 병원에서는 담배를 피울 수 없어요.
Also possible for focus/contrast:
- 담배를 병원에서는 피울 수 없어요. (focusing the place)
- 병원에서는 담배는 피울 수 없어요. (contrast on 담배 vs other things) Keep the verb phrase at the end for clarity.

Why not say 피울 수 안 돼요?

Two different patterns are being mixed:

Ability/possibility: V-ㄹ/을 수 있다/없다 → 피울 수 없어요.
Permission/prohibition with 되다: V-(으)면 안 돼요 → 피우면 안 돼요. Use one or the other; don’t combine 수 with 안 돼요.

What do 금연, 흡연, and 흡연 구역/금연 구역 mean?

금연: no smoking (literally “forbid + smoke”); also “to quit smoking” depending on context.
흡연: smoking.
흡연 구역: smoking area.
금연 구역: non-smoking area.

On signs you’ll often see 금연 or 금연 구역 instead of a full sentence.