Learn Hardcore Korean: naneun doseogwaneseo soseolchaegeul billyeosseo.

도서관 means “library.”
-에서 indicates the place where an action happens (“at,” “in,” or “from”).
So 도서관에서 = “at the library (where the borrowing took place).”
In contrast, -에 marks a destination or location of existence (“to/in”), not the site of an action.

What role does 소설책을 play here? Why is -을 attached?

소설책 = “novel book” (i.e. “a novel”).
-을 is the direct object particle, marking what is being acted upon.
Thus 소설책을 means “(the) novel” as the thing you borrowed.

What does 빌렸어 mean, and what is its dictionary form?

빌리다 is the dictionary form, meaning “to borrow.”
빌렸어 is the informal, past-tense, declarative form, so it means “(I) borrowed.”

How do you get 빌렸어 from 빌리다 step by step?

Take the verb stem 빌리-.
Add the past-tense marker -었-, giving 빌리 + 었 → 빌렸 (리 + 었 contracts to 렸).
Add the informal ending -어, resulting in 빌렸 + 어 = 빌렸어.

Does 빌리다 ever mean “to lend,” or is it always “to borrow”?

빌리다 means “to borrow” (you receive something from someone).
The opposite, “to lend,” is 빌려주다 (빌려 + 주다 = “to lend to someone”).

Why is the verb placed at the end of the sentence in Korean?

Korean uses a Subject-Object-Verb (SOV) word order. In other words, the verb always comes last:
Subject/Topic → (Location) → Object → Verb.
Hence 나는 도서관에서 소설책을 빌렸어 follows that pattern.

What’s the difference between the topic marker -는 and the subject marker -가?

-는 (as in 나는) introduces or highlights the topic, often implying contrast or general background.
-가 focuses on the grammatical subject, usually presenting new or emphasized information.
In this sentence, using -는 makes “I” the topic (“As for me…”) rather than merely marking “I” as the subject.