Learn Hardcore Korean: jeoneun teukhi jumare doseogwaneseo gongbuhaeyo. - I especially study at the library on weekends.

는/은 marks the topic: it sets up “as for me” and can imply mild contrast or a general/habitual statement.
가/이 marks the grammatical subject and often highlights or identifies the doer as new/important information.
In this sentence, 저는 sounds natural because you’re making a general statement about your own routine. 제가 특히 주말에… would sound like you’re answering “Who studies at the library on weekends?” with “I do.”

Why is it 주말에 but 도서관에서? When do I use 에 vs 에서?

에 marks time points and static locations: 주말에 (on weekends), 도서관에 있어요 (I’m at the library).
에서 marks the location where an action happens: 도서관에서 공부해요 (I study at the library).
So we use 주말에 (time) and 도서관에서 (place of action).

Can I say 도서관에 공부해요?

No. With action verbs like 공부하다, use the place-of-action marker 에서: 도서관에서 공부해요.
Use 에 with motion or existence: 도서관에 가요 (I go to the library), 도서관에 있어요 (I’m at the library).

What exactly does 특히 modify here, and can I move it?

In 저는 특히 주말에 도서관에서 공부해요, 특히 most naturally scopes over 주말에 = “especially on weekends.”
You can move it to change the focus:
- 저는 주말에 특히 도서관에서 공부해요. = On weekends, especially at the library (as opposed to other places).
- 저는 주말에는 특히 도서관에서 공부해요. = As for weekends (contrast), especially at the library.
Avoid clunky orders like 도서관에서 특히 주말에 공부해요; it’s grammatical but sounds unnatural. Typical flow is time > place > verb.

Could I say 주말에는 instead of 주말에?

Yes. 주말에는 adds a topic/contrast nuance: “As for weekends (compared to weekdays), …” It subtly emphasizes the weekend timeframe.

Do I have to include 저는? Can I drop it?

You can drop it if context already makes the subject clear: 특히 주말에 도서관에서 공부해요.
Keep 저는 when introducing yourself as the topic or when contrasting with others.

Why isn’t there an object marker? Should it be 공부를 해요?

공부하다 is a set verb meaning “to study,” so 공부해요 is complete.
You can also say 공부를 해요 (treating 공부 as a noun + object), which is also correct. The nuance difference is minimal; 공부를 해요 can sound a bit more emphatic or careful in some contexts. Both are very common.

What politeness level is 공부해요? What are other forms (and what about 나/저)?

공부해요: polite, standard in most everyday situations.
공부합니다: formal-polite (presentations, announcements, very polite speech).
공부해: casual (friends, younger people). Also match pronouns to politeness:
With -요 style, use 저는 (not 나는).
With casual style, use 나는 (not 저는).

Is 특히 the same as 특별히 or 주로?

특히 = especially/particularly (picks out a special case among others). Example: 과일을 특히 좋아해요 (I especially like fruit).
특별히 = specially/expressly (done in a special way or for a special reason). Example: 오늘은 특별히 일찍 왔어요 (I came early especially today).
주로 = mainly/for the most part (typical tendency). Example: 주로 집에서 공부해요 (I mainly study at home).
In your sentence, 특히 is the right choice.

Why isn’t there a word for “the” before “library”?

Korean has no articles like “a/the.” 도서관 can mean “a library” or “the library,” depending on context. If you need to specify, use demonstratives or modifiers: 그 도서관 (that library), 우리 도서관 (our library), 학교 도서관 (the school library).

Can I omit particles like 에 or 에서 in casual speech?

Native speakers sometimes drop particles in very casual speech, but:

Time/place markers (에, 에서) are less commonly dropped than 를/은/는/이/가.
Safer options are natural contractions: 주말엔 (= 주말에는), and colloquially 도서관서 (= 도서관에서).
As a learner, keep 에/에서 to stay clear and correct.

Does 에서 ever mean “from”?

Yes. 에서 has two common uses:

Place of action: 도서관에서 공부해요 (study at the library).
Starting point/origin: 서울에서 왔어요 (I came from Seoul), 부산에서 서울까지 (from Busan to Seoul).
For time “from,” prefer 부터: 주말부터 (from the weekend).

Any pronunciation tips for this sentence?

특히 is pronounced roughly “teuk-hi,” often heard as a crisp [트키] because of strong aspiration.
도서관에서 links smoothly: 관에서 sounds like [과네서].
주말에 sounds like [주마레].
저는 is [저는], and 공부해요 is [공부해요].
Keep syllable timing even; don’t stress words like in English.

How would I say “I go to the library and study, especially on weekends”?

저는 특히 주말에 도서관에 가서 공부해요.
Here 가서 links the actions “go (to the library)” and “study.”

What’s the typical word order for time, place, and the verb?

Korean prefers: time > place > other details > verb.
Your sentence follows that: 주말에 (time) 도서관에서 (place) 공부해요 (verb).

What tense/aspect does 공부해요 express here? How do I say past or future?

In context it’s present/habitual (“I study”).

Past: 공부했어요 (I studied).
Future/intention: 공부할 거예요 (I will study / I’m going to study).