eoje billin soseoreul oneul achime bannaphaesseo.

I returned the novel I borrowed yesterday this morning.

Breakdown of eoje billin soseoreul oneul achime bannaphaesseo.

• ~을: object particle
• 어제: yesterday
• 오늘: today
• 아침: morning
• ~에: time particle
• 빌리다: to borrow
• 반납하다: to return
• 소설: novel

Questions & Answers about eoje billin soseoreul oneul achime bannaphaesseo.

Where is the subject? Why isn’t it written?

• Korean drops subjects when they’re obvious from context. Here it’s understood as I (or we).
• To say it explicitly:
  • Topic: 나는/저는 어제 빌린 소설을 오늘 아침에 반납했어(요).
  • Subject (often contrastive): 내가/제가 어제 빌린 소설을 오늘 아침에 반납했어(요).

How does 어제 빌린 소설 work? Why 빌린?

• It’s a relative clause: 빌리다 (to borrow) + past attributive -(으)ㄴ → 빌린.
• So 어제 빌린 소설 = “the novel (I) borrowed yesterday.”
• Forming past modifiers:
  • Verb stem + -은/‑ㄴ (consonant → -은, vowel → -ㄴ): 먹다 → 먹은, 가다 → 간, 빌리다 → 빌린.

Can I say 어제 빌렸던 소설 or 어제 빌렸어? What’s the difference?

• 빌린 modifies a noun (attributive) → “the novel (I) borrowed…”
• 빌렸어 is a finite verb → “I borrowed…”
• 빌렸던 adds a nuance of “that I had borrowed before/previously” or a bit of reminiscence/contrast. It’s okay here, but 빌린 is the neutral choice.

Why 소설을 and not 소설이? When do I use 을/를?

• 을/를 marks the direct object. 소설 ends with a consonant, so 소설을 (vowel-ending nouns take 를).
• In casual speech the object particle can be dropped: 어제 빌린 소설 오늘 아침에 반납했어 (still natural).

What politeness level is 반납했어? How do I make it polite or formal?

• 반납했어 = casual intimate past (to friends/peers).
• Polite: 반납했어요.
• Formal: 반납했습니다.
• With strangers, elders, or in service situations, prefer -요 or -습니다 forms.

Is 반납하다 the right verb for “return”? How is it different from 돌려주다?

• 반납하다 = to return something to an institution/system (library, rental shop). Ex: 도서관에 반납하다.
• 돌려주다 = to give something back to a person. Ex: 친구에게 책을 돌려줬어.
• Honorific to a person: 돌려드렸어요 (to a teacher, boss, etc.).

Why 오늘 아침에 with -에? Can I say 오늘 아침?

• -에 marks a specific point in time, so 아침에, 3시에, 월요일에.
• 어제/오늘/내일 typically don’t take -에 by themselves, but when combined with a time-of-day noun you often use -에: 오늘 아침에, 내일 저녁에.
• 오늘 아침 (without -에) is also heard; -에 just makes the time point explicit.

Can I change the word order, like putting the time first?

• Yes. Korean word order is flexible (verb-final). Natural variants:
  • 오늘 아침에 어제 빌린 소설을 반납했어.
  • 어제 빌린 소설을 오늘 아침에 반납했어.
• Fronting an element puts slight emphasis on it (time-first emphasizes when; object-first emphasizes what).

Can I use 은/는 on the object: 어제 빌린 소설은?

• Yes. 어제 빌린 소설은 오늘 아침에 반납했어 topicalizes the book: “As for the novel I borrowed yesterday, I returned it this morning,” often implying contrast or setting up further info.

Why not 어제 빌린 소설이 오늘 아침에 반납했어?

• 이/가 marks the subject. That sentence says “The novel returned (something) this morning,” which is nonsense. The subject is the (omitted) speaker.
• If you want to mark the book, use 은/는 as topic (see above), not 이/가.

How is 반납했어 pronounced?

• Due to assimilation, 반납했어 is commonly heard as [반나패써] (ban-na-pae-sseo).
• 어제 빌린 is [어제 빌린] (eo-je bil-lin), with the double ㄹ flowing smoothly.

What’s the dictionary form and breakdown of 반납했어?

• Dictionary form: 반납하다.
• Past: 반납하
  • -였/었- → 반납했- (contraction).
• Ending: -어/요 → 반납했어 / 반납했어요.

Can I use 책 or 소설책 instead of 소설?

• 소설 = a novel (genre-specific).
• 책 = book (general).
• 소설책 = a book that is a novel; a bit more colloquial/redundant but common.
• All can be fine depending on how specific you want to be.

How do I add “at/to the library”? 에 or 에서?

• Target/destination (return to): 도서관에 반납했어 (most common with 반납하다).
• Location of the action (at): 도서관에서 반납했어 is also heard, focusing on where the act took place rather than the target. Both are acceptable; 도서관에 반납하다 is the default collocation.

How do I make it a question or negative?

• Question (casual/polite): 반납했어? / 반납했어요?
• Negative: 반납 안 했어 / 반납 안 했어요 (didn’t return), or 반납 못 했어 / 못 했어요 (couldn’t return).