banghagiraseo hakgyoga joyonghaeyo.

-이라서 gives a reason or cause, like because, since, or as in English.

So 방학이라서 학교가 조용해요 means something like:

• Because it’s vacation, the school is quiet.
• Since it’s school vacation, the school is quiet.

Grammar-wise, -이라서 is attached to a noun. It comes from 이다 plus -아서/어서.

• noun ending in a consonant: -이라서
• noun ending in a vowel: -라서

Since 방학 ends in a consonant, it becomes 방학이라서.

Because 방학 is a noun, not a verb or adjective.

For nouns, Korean uses the copula 이다 before connecting to -아서/어서, which gives:

• 방학 + 이라서 → 방학이라서

You cannot normally say 방학해서 because -해서 attaches to verbs/adjectives or certain noun-based forms like 공부하다.

Also, 방학여서 is not the correct form here. The noun pattern is:

• consonant-ending noun + 이라서
• vowel-ending noun + 라서

So 방학이라서 is the correct grammar.

Because -이라서 already attaches directly to the noun and includes the idea of being.

In other words:

• 방학이라서 = because it is vacation

The 이 here is not a subject marker. It is part of the copula-related form 이라서.

So you do not add another particle before it. You would not say 방학이이라서.

가 marks 학교 as the thing being described by 조용해요.

So the sentence is focusing on the fact that the school is quiet.

Compare:

• 학교가 조용해요 = The school is quiet. / focus on the school as the thing that is quiet
• 학교는 조용해요 = As for the school, it is quiet. / topic or possible contrast

Using 는 might sound like you are contrasting it with something else, for example:

• 학교는 조용한데 집은 시끄러워요.
  • The school is quiet, but the house is noisy.

In your sentence, 가 is very natural because it simply presents school as the subject of the description.

조용해요 comes from the dictionary form 조용하다, which means to be quiet or to be peaceful/calm.

Although English calls quiet an adjective, in Korean this type of word behaves like a descriptive verb.

The form changes like this:

• 조용하다 → dictionary form
• 조용해요 → polite present-style form

So 조용해요 means:

• is quiet
• is calm
• is peaceful

Depending on context, 조용하다 can describe:

• a place: quiet
• a person: quiet
• an atmosphere: calm

Here it describes 학교, so the school is quiet.

This is a very common Korean conjugation pattern.

조용하다 is made of:

• 조용
  • 하다

When 하다 is conjugated in the polite present style, it becomes 해요:

• 하다 → 해요

So:

• 조용하다 → 조용해요

You will see the same thing in many other words:

• 공부하다 → 공부해요
• 필요하다 → 필요해요
• 이상하다 → 이상해요

So 조용해요 is just the normal polite form of 조용하다.

Yes, in a way. Korean often leaves out subjects when they are clear from context.

In English, you often need something like:

• It’s vacation, so the school is quiet.

But Korean does not need a dummy subject like it.

So 방학이라서 naturally means:

• because it is vacation
• because it’s school vacation

The sentence sounds complete without adding any extra subject.

방학 specifically refers to a school break or school vacation, such as:

• summer vacation
• winter vacation
• a break between school terms

It is not the general word for any vacation or holiday trip.

So in this sentence, 방학이라서 strongly suggests that school is not in normal session, which explains why 학교가 조용해요.

Yes. 방학이어서 and 방학이라서 are both possible.

In everyday speech, 이라서/라서 is very common and natural after nouns, so 방학이라서 sounds completely normal.

Both mean essentially the same thing here:

• 방학이라서 학교가 조용해요
• 방학이어서 학교가 조용해요

For many learners, -이라서 / -라서 is the more useful pattern to remember first for noun-based reasons.

A natural pronunciation is close to:

• 방학이라서 → 방하기라서
• 학교가 → 학꾜가

So the whole sentence sounds roughly like:

• 방하기라서 학꾜가 조용해요

A few pronunciation notes:

• In 방학이라서, the final consonant links into the following vowel sound.
• In 학교, the ㄱ sound becomes tense in pronunciation, so it sounds like 학꾜.

You do not need to spell it differently, but it helps to know why native speech may sound different from the written form.

Usually it expresses a reason, so because is often a good translation, but the exact English wording depends on context.

It can also feel like:

• since
• as
• because it’s the case that...

In this sentence, because works very well:

• Because it’s vacation, the school is quiet.

But the Korean is often a little smoother and less heavy than English because. It simply connects the reason and result in a natural way.