Learn Hardcore Korean: i hotel robineun geumyeon guyeogieyo. - This hotel lobby is a non-smoking area.

-는 is the topic marker. It marks 이 호텔 로비 (this hotel’s lobby) as the topic and frames what follows as information about it.
Nuance: using -는 often sets up contrast or backgrounded/given information. It can imply “as for the lobby (maybe other areas differ) …”
It attaches to the last word of the noun phrase: the whole NP is 이 호텔 로비, so the marker goes on 로비 → 로비는.

Is 이 here the subject marker -이?

No. 이 here is the demonstrative determiner meaning this. The subject marker -이 attaches after a noun (e.g., 로비가 / 로비가), while this 이 comes before a noun to modify it: 이 호텔 = “this hotel.”

Do I need 의 between 호텔 and 로비 (i.e., 이 호텔의 로비)?

Both are possible:
- 이 호텔 로비 (natural and very common in speech; the possessive 의 is omitted).
- 이 호텔의 로비 (more explicit/official/written).
Korean often drops 의 between two nouns when the relationship is clear.

Why is it 구역이에요 and not 구역예요? What about 입니다?

Rule: after a noun ending in a consonant, use 이에요; after a vowel, use 예요.
- 구역 ends in consonant ㄱ → 구역이에요.
- Example: 도서관이에요, 공원이에요 vs. 학교예요, 회사예요.
입니다 is a more formal polite ending. On signs, you will often see 금연구역입니다.

Should 금연 구역 be written as one word (금연구역) or two?

The standard compound noun form is commonly written as 금연구역 (no space).
You will also see 금연 구역 with a space in informal contexts. For formal writing and signage, prefer 금연구역.

How do you pronounce the sentence naturally?

Slow, syllable-based: i ho-tel ro-bi-neun geum-yeon gu-yeok-i-e-yo
Natural sound changes:
- 호텔 ≈ [호텔]
- 금연 → [그면] (the m + y sound coalesces to “myeon”)
- 구역이에요 → [구여기에요] (the final ㄱ in 역 links to the following 이)
Put together: [이 호텔 로비는 그면 구여기에요].

Can I use -가 instead of -는 (i.e., 이 호텔 로비가 금연 구역이에요)?

Yes, it’s grammatically fine.
Nuance:
- 로비는 … gives a topic/contrast feel (“as for the lobby…”).
- 로비가 … presents it as new, focal information (“the lobby is (the one that is) a non-smoking area”).
In everyday statements and signs, the topic version is very common, but either can work depending on context.

Could I just say 여기는 금연이에요 or 로비는 금연이에요?

Yes.
- 여기는 금연이에요 = “It’s non-smoking here.” Very common spoken phrasing.
- 로비는 금연이에요 = “The lobby is non-smoking.” Slightly shorter and natural.
The original 금연 구역 is a bit more formal/explicit (“non-smoking area/zone”).

Why does the particle attach to 로비 and not 호텔? Could I say 이 호텔은 로비가 금연 구역이에요?

Particles attach to the last word of the noun phrase they mark. The topic is the entire phrase 이 호텔 로비, so the marker goes on 로비 → 로비는.
You can also topicalize the hotel instead:
- 이 호텔은 로비가 금연 구역이에요.
- Meaning: “As for this hotel, the lobby is a non-smoking area.” This contrasts the lobby with other areas of the hotel.

What’s the difference between 구역 and 지역? Why not 금연 지역?

구역: zone/section within a facility (bounded, designated space). Fits signage like “no-smoking zone.”
지역: region/area in a broader geographical sense.
For places inside a building (lobby, hallway), 금연구역 is the standard choice.

Does 금연 mean “no smoking” or “quitting smoking”?

Both, depending on context:

On signs or as a modifier (e.g., 금연구역, 금연실) it means “no smoking.”
As a verb/noun about personal habit (금연하다, 금연 중) it means “to quit/abstain from smoking.”

How would I make this into a question politely?

Casual-polite: 이 호텔 로비는 금연 구역이에요?
Neutral-polite (softer): 이 호텔 로비는 금연 구역인가요?
Formal-polite: 이 호텔 로비는 금연 구역입니까?

Can I use a location particle like -에서 or -에는 to express prohibition?

Yes, that’s another natural way:

이 호텔 로비에서는 흡연이 금지되어 있어요. (“In the hotel lobby, smoking is prohibited.”)
-에서는 / -에는 focuses on the location; 금지되어 있어요 states the prohibition explicitly.

Why is it 로비는 (not 로빈은) and when would I use -은 instead?

The topic marker is -는 after a vowel-final noun and -은 after a consonant-final noun.
- 로비 ends in a vowel → 로비는.
- If the noun ends in a consonant: 식당은 금연구역이에요.