Learn Hardcore Korean: annae deseukeueseo hwanseung hoessureul mureobwayo. - I ask the information desk about the number of transfers.

-에서 marks the place where an action happens (at). Here it means the action of asking happens at the information desk.
-에 marks location/destination or a static state (to/at). If you want to emphasize going there first, say 안내 데스크에 가서 ….
With institutions, -에 can mark the target you ask (e.g., 회사에 물어봤어요), but with a physical desk, -에서 is the clearest when you mean “at the desk.”

Why is the object marker on 환승 횟수 and not on 환승?

The object is the whole noun phrase 환승 횟수 (“the number of transfers”). 환승 modifies 횟수, so the marker attaches to the head noun phrase: 환승 횟수 + 를 → 환승 횟수를. If you want to treat “transfer” as the object, you’d rephrase: 환승을 몇 번 하는지 물어봐요.

What’s the difference between 물어봐요, 물어요, 질문해요, and 문의해요?

물어봐요: Everyday “ask.” Most common and natural in conversation.
물어요 (from 묻다): Also “ask,” a bit crisper/literary; fully correct.
질문해요: “Ask a question” (focus on the act of questioning), e.g., 선생님께 질문해요.
문의해요: “Make an inquiry” (business/formal), e.g., 고객센터에 문의하세요.
Honorific to the person asked: 여쭤봐요 / 여쭙니다 (when speaking to/about someone you honor).

Does 물어봐요 literally mean “try asking”? Is there a nuance difference vs 물어요?

-아/어 보다 often means “try doing,” but with 물어보다 the “try” nuance is usually bleached, so it just means “ask.”
물어요 is the bare “ask.” Both are fine; 물어봐요 sounds the most natural in speech.
If you want to emphasize “give it a try,” add 한번: 한번 물어봐요/물어볼게요.

How do I mark the person I’m asking (e.g., the staff at the desk)?

Use 에게/한테 after the person:

안내 데스크 직원한테 환승 횟수를 물어봐요. More polite toward the person:
안내 데스크 직원분께 여쭤봐요. Avoid 안내 데스크한테 (a desk isn’t a person). Use …에서 직원한테 instead.

Is 안내 데스크 natural? Are there other words or spacing rules?

안내 데스크 is common in public places. You’ll also see 안내데스크 (no space); both appear in real-life signage.
Native alternatives include 안내소 (“information booth/counter”) and 안내 창구 (“information window/counter”).

What’s the difference between 횟수, 번, and 회?

번: Native counter used after numbers in everyday speech (e.g., 두 번, 세 번).
회: Sino-Korean counter, more formal or in set phrases (e.g., 1회, 3회 이용).
횟수: The noun “number of times,” good with verbs like 확인하다/물어보다 or with 많다/적다/제한. Hence 환승 횟수 fits well here.

Why is it spelled 횟수 and not 회수? How do I pronounce it?

횟수 uses a linking ㅅ (사이시옷) and means “number of times.” 회수 is a different word meaning “collection/recovery/recall.”
Pronunciation: 횟수 is pronounced with a tense ㅆ in the second syllable, roughly like “hwet-ssu.”

Can I drop the object marker 를 in 횟수를?

Yes. In casual speech you can say 안내 데스크에서 환승 횟수 물어봐요. It remains natural if the meaning is clear. Keep 을/를 in writing or when the sentence gets complex.

Who is the subject here? How do I make it explicit?

Korean often omits the subject. 물어봐요 could mean “I/you/we/they ask,” depending on context. To specify:

“I”: 제가/저는
“You” (polite conversations usually avoid direct “you”): rephrase politely, or use a title (선생님은), or just context.
“They/He/She”: 그 사람이/그분이

Can I change the word order?

Yes. Both are natural:

안내 데스크에서 환승 횟수를 물어봐요.
환승 횟수를 안내 데스크에서 물어봐요. Keep the modifier and its noun together; don’t split 환승 and 횟수.

How do I say “ask how many transfers there are” with an embedded question?

Use -인지 / -는지:

안내 데스크에서 환승 횟수가 몇 번인지 물어봐요.
안내 데스크에서 몇 번 환승해야 하는지(=몇 번 갈아타야 하는지) 물어봐요.

Can I say “ask about the number of transfers” using 에 대해?

Yes. …에 대해(서) means “about”:

안내 데스크에서 환승 횟수에 대해서 물어봐요. It’s slightly more explanatory/formal; the original with the object marker is also perfectly natural.