Learn Hardcore Korean: yeongeopsigani kkeutnasseunikka pojangeun an dwaeyo. - Since business hours are over, takeout isn’t possible.

Because 끝나다 is an intransitive verb (“to end”), the thing that ends is the grammatical subject: 영업시간이 끝나다. Using 은/는 would also be acceptable, but it would topicalize or contrast it: 영업시간은 끝났으니까… (“As for business hours, since they’re over…”). The original with 이 is a straightforward subject statement.

What’s the nuance difference between -아서/어서 and -으니까 in 끝났으니까?

Both can mean “because/since.”

-으니까 often sounds more like giving a clear reason or justification and can precede commands/requests.
-아서/어서 is a bit more neutral/explanatory and cannot precede imperatives or suggestions. Here, 끝났으니까 feels firm, like stating a rule: “Since hours are over, [rule applies].” 끝나서 would also be fine and polite.

Why is it 포장은 안 돼요 with 은? Could it be 포장이 안 돼요 or 포장을 안 해요?

포장은 안 돼요 uses the pattern “N은/는 안 되다” to state rules/permissions: “As for takeout, it’s not allowed/possible.”
포장이 안 돼요 is also natural: “Takeout is not possible.”
포장을 안 해요 focuses on the staff’s action: “We don’t do takeout.” It can sound more like a policy choice rather than a rule/permission.

What does 안 돼요 literally mean, and why use 되다?

되다 = “to become; to work; to be acceptable/possible/permitted.”
안 되다 = “not possible/allowed/working.”
So 포장은 안 돼요 literally means “As for takeout, it doesn’t (work)/isn’t allowed,” which is the standard way to refuse based on rules or feasibility.

Is it spelled 안돼요 or 안 돼요? And why is it 돼요, not 되요?

Correct spacing: 안 돼요 (two words). Writing 안돼요 is a common mistake.
Morphology: 되다 + 어요 → 되어요 → 돼요. So 돼요 is correct; 되요 is nonstandard.

Is 영업시간 written as one word or two? 영업시간 vs 영업 시간

Both appear, but as a common compound noun, 영업시간 (no space) is standard and widely preferred in signage and everyday writing.

Can I say 영업이 끝났으니까 instead of 영업시간이 끝났으니까?

Yes. 영업이 끝났으니까 means “since business is over,” which is natural and colloquial. 영업시간이 끝났으니까 is a bit more precise (“since business hours have ended”).

Why is the past tense used in 끝났으니까 when we’re talking about the present situation?

Korean commonly uses the past to mark a completed state that now holds: the hours have ended already, so the rule applies now. 끝나니까 would suggest a general/recurring cause (“since they end…”) or “since they’re ending,” which is less natural here.

Is 안 돼요 polite enough for a customer? What’s a more formal version?

안 돼요 is polite but casual. Service staff often use a more formal tone:

포장은 안 됩니다.
죄송하지만 영업시간이 끝나서 포장은 어렵습니다.
포장은 불가합니다. 죄송합니다.

What’s the difference between 안 돼요, 못 해요, and 할 수 없어요 here?

안 돼요: rule/permission or possibility (“not allowed/doesn’t work”). Most idiomatic for policies.
못 해요: inability due to circumstances/skill (“can’t do it”).
할 수 없어요: inability/constraint in a more literal sense (“cannot do it”). Acceptable, but policy-wise 안 돼요/안 됩니다 sounds more native.

How would I contrast dine-in vs takeout, like “Dine-in is okay, but takeout isn’t”?

매장 취식은 가능하지만 포장은 안 됩니다.
More casual: 드시는 건 괜찮은데 포장은 안 돼요.

Is 포장 the right word for “to-go”? I also hear 테이크아웃.

Both are used.

포장(하다) is standard for food packaging/takeout: 포장해 주세요 (“Please make it to-go”).
테이크아웃 is common in cafés: 테이크아웃 될까요? or 테이크아웃으로요. Either is understood; 포장 works everywhere.

Can you break down 끝났으니까 morphologically?

끝나- (verb stem “end”)
-았- (past/completed: 끝났-)
-으니까 (reason “since/because”) Together: 끝났 + 으니까 → 끝났으니까 (“since [it] has ended”).

Any pronunciation tips? I keep wanting to say 되요 and not 돼요.

돼요 is pronounced like “dwae-yo” [dwae-yo], not “doe-yo.”
In fast speech, 끝났으니까 sounds like [끈나쓰니까] because the past marker merges: -았/었- + 으니까 often surfaces like “써니까.”

Can I change the word order to focus on takeout first?

Yes. 포장은 영업시간이 끝났으니까 안 돼요 is natural and puts immediate focus on the restriction. Korean allows such reordering for emphasis without changing the core meaning.