eonnineun seongjeogeul olliryeogo jumalmada hagwoneseo balpyo yeonseubeul hae.

는 is the topic marker, while 가 is the subject marker.

In this sentence, 언니는 sets up older sister as the topic: as for my older sister... It gives a natural, descriptive tone, as if the speaker is talking about what she does regularly.

If you used 언니가, it would sound more like you are specifically identifying who does this, often in contrast to someone else or as new information.

So here, 언니는 feels very natural for a general statement about her habits.

언니 means older sister, but it is used by a female speaker.

A Korean speaker uses different words for older siblings depending on the speaker’s gender:

• female speaker → 언니 = older sister
• male speaker → 누나 = older sister

So if the speaker says 언니, that strongly suggests the speaker is female.

It can also be used for an older female who is not literally your sister, such as a close older female friend or acquaintance, depending on context.

This part is made of:

• 성적 = grades
• 을 = object marker
• 올리려고 = in order to raise/improve

The key grammar is -려고, which expresses intention or purpose: in order to, with the intention of.

So 성적을 올리려고 means:

• in order to improve her grades
• because she wants to raise her grades

It connects the reason/purpose to the main action that follows.

Because 올리다 is a transitive verb, meaning it takes an object.

• 성적을 올리다 = to raise/improve grades

Here, grades are the thing being improved, so they take 을/를.

Compare:

• 성적이 오르다 = grades go up
• 성적을 올리다 = to raise/improve grades

So:

• 오르다 is intransitive
• 올리다 is transitive

That is why 성적을 is correct here.

The grammar pattern is:

• verb stem + -려고
• or verb stem + -으려고

Which form you use depends on how the verb stem ends.

• If the stem ends in a vowel or ㄹ, you usually use -려고
• If it ends in most other consonants, you use -으려고

Here the verb is 올리다.
Its stem is 올리-, which ends in a vowel, so it becomes 올리려고.

Examples:

• 가다 → 가려고
• 먹다 → 먹으려고
• 살다 → 살려고

Usually, yes.

In a sentence with -려고, the person who has the intention or purpose is normally the same person doing the main action.

Here:

• 언니는 wants to improve her grades
• 언니는 practices presentations

So the subject is understood to be the same in both parts, which fits -려고 very naturally.

That is one reason this sentence sounds smooth and standard.

주말마다 means every weekend.

The particle -마다 means every or each, and it attaches directly to a noun.

Examples:

• 주말마다 = every weekend
• 하루마다 = every day
• 수업마다 = every class

So in this sentence, it tells you the action happens repeatedly, weekend after weekend.

Because 에서 marks the place where an action happens.

Here, the action is 발표 연습을 해 = practices presentations, and that action takes place at the academy/cram school.

So:

• 학원에서 연습하다 = practice at the academy

By contrast, 에 is often used for:

• destination: 학원에 가다 = go to the academy
• existence/location with some verbs: 학원에 있다 = be at the academy

Since this sentence is about doing an action in a place, 에서 is correct.

학원 usually refers to a private academy, often called a cram school in English.

It is not exactly the same as a regular school (학교). In Korea, 학원 often means a place students go outside normal school hours to study subjects such as:

• math
• English
• test prep
• speaking/presentation skills

So 학원에서 suggests she is doing this practice in an organized private-study setting.

Literally, it is:

• 발표 = presentation, speech, announcement
• 연습 = practice
• 연습을 하다 = to do practice / to practice

So 발표 연습을 해 literally means does presentation practice.

A more natural English translation would be:

• practices presentations
• practices giving presentations
• does presentation practice

In Korean, it is very common to use a noun plus 연습하다 or 연습을 하다.

해 is the casual, non-polite form of 하다.

So the sentence ending tells you about the speech style:

• 해 = casual/intimate
• 해요 = polite everyday speech
• 한다 = plain written/narrative style

This means the sentence sounds like something said casually, perhaps in conversation with a friend, younger person, or in informal narration.

The same sentence in polite speech would be:

• 언니는 성적을 올리려고 주말마다 학원에서 발표 연습을 해요.

Yes, there is a small nuance difference, though both can work.

• 발표 연습을 하다 = to do presentation practice
• 발표를 연습하다 = to practice presentations

The first treats presentation practice as a kind of activity or set phrase.
The second treats presentation more directly as the thing being practiced.

In everyday Korean, noun + 연습을 하다 is very common, so 발표 연습을 해 sounds natural and idiomatic.

The sentence can be broken down like this:

• 언니는 = as for my older sister
• 성적을 올리려고 = in order to improve her grades
• 주말마다 = every weekend
• 학원에서 = at the academy
• 발표 연습을 해 = she practices presentations

So the structure is basically:

Topic + purpose + time/frequency + place + main action

That word order is very natural in Korean, where details like purpose, time, and place often come before the final verb.

Yes. 발표 can mean things like:

• presentation
• speech
• announcement
• public speaking

The exact meaning depends on context.

In this sentence, because it is 발표 연습 at an 학원, and the purpose is to improve grades, the most natural interpretation is something like:

• presentation practice
• public-speaking practice
• practice giving class presentations

So while 발표 can be broader, presentation is probably the best fit here.