seonsaengnimi bangapge insahae jusyeosseoyo.

A useful breakdown is:

• 선생님이 = the teacher
  • subject marker 이
• 반갑게 = warmly / in a glad way / as if happy to see someone
• 인사해 = greet / say hello
• 주셨어요 = did for someone
  • honorific + past polite ending

So the sentence is built like:

The teacher + warmly + greeted + for me/us

That last part, -아/어 주다, often adds the feeling that the action was done for the benefit of someone, often the speaker.

이/가 marks the subject of the sentence.

So 선생님이 means the teacher is the person who performed the action.

In this sentence, the teacher is the one who greeted someone, so 이 is natural.

A learner might compare it to 선생님은:

• 선생님이 focuses more on who did it
• 선생님은 would sound more like as for the teacher...

Both can be possible in different contexts, but 이 is a very normal choice when simply stating what happened.

반갑게 is the adverb form of 반갑다.

• 반갑다 = to be glad / pleased to see someone
• 반갑게 = gladly, warmly, in a pleased way

The ending -게 often turns an adjective into something that describes how an action is done.

So:

• 반갑다 describes a feeling
• 반갑게 인사하다 means to greet someone warmly / happily

That is why 반갑게 works before the verb 인사하다.

Here, 반갑게 does not just mean glad in a simple dictionary sense. It describes the manner of the greeting.

It suggests something like:

• warmly
• with pleasure
• as if happy to see me/us
• in a friendly, welcoming way

So it is not just a neutral hello. It gives a positive emotional tone to the greeting.

인사해 comes from the verb 인사하다, which means to greet or to say hello.

Conjugation:

• 인사하다
• stem used in this pattern: 인사해

This happens because 하다 verbs often become 해 in conjugation:

• 공부하다 → 공부해
• 인사하다 → 인사해

So in this sentence, 인사해 주셨어요 is built from 인사하다.

This is one of the most important points in the sentence.

• 인사하셨어요 = (the teacher) greeted
• 인사해 주셨어요 = (the teacher) greeted me/us for my/our benefit

The pattern -아/어 주다 often means someone did something for someone else. It can sound appreciative, warm, or personal.

So 인사해 주셨어요 can imply something like:

• The teacher kindly greeted me/us
• The teacher greeted me/us, which I appreciate
• The teacher went out of their way to greet me/us

It is not always dramatically different in English translation, but in Korean it adds a meaningful nuance.

주셨어요 can be broken down like this:

• 주- = from 주다 (to give; in grammar patterns, do for someone)
• -시- = honorific marker, showing respect toward the subject
• -었- = past tense
• -어요 = polite ending

So:

주 + 시 + 었 + 어요 → 주셨어요

This means the speaker is being respectful toward 선생님, which makes sense because the subject is the teacher.

Because the subject is 선생님, and Korean commonly uses honorific grammar when talking about a teacher.

The marker -시- shows respect toward the person doing the action.

Compare:

• 주었어요 = gave / did for someone
• 주셨어요 = gave / did for someone, with respect to the subject

Since the teacher is someone worthy of respect in Korean, 주셨어요 sounds natural and appropriate.

Korean often leaves out things that are understood from context.

In this sentence, the person being greeted is not explicitly stated, but it is usually understood as:

• me
• us
• someone in the situation

So the full idea could be something like:

• 선생님이 저에게 반갑게 인사해 주셨어요.
• The teacher warmly greeted me.

But Korean very often omits 저에게, 저를, or similar words when they are obvious.

Yes, it could.

• 선생님이 반갑게 인사해 주셨어요
• 선생님께서 반갑게 인사해 주셨어요

Both are possible.

The difference is that 께서 is a more honorific subject marker than 이/가. Because the subject is 선생님, 께서 can sound especially respectful.

Still, 선생님이 is very common and natural in everyday polite speech.

Yes, it is natural.

It means to greet someone:

• warmly
• happily
• in a friendly way

Korean often uses an adverb + 인사하다 to show the style of greeting.

For example:

• 밝게 인사하다 = greet brightly/cheerfully
• 정중하게 인사하다 = greet politely
• 반갑게 인사하다 = greet warmly, as if glad to see someone

So this phrase sounds normal and idiomatic.

The sentence does more than just report a greeting.

It suggests:

• the teacher greeted the speaker pleasantly
• the speaker feels that greeting as a positive action
• the sentence is polite and respectful toward the teacher

Because of 반갑게, the greeting sounds warm.
Because of -아/어 주셨어요, it can sound appreciative.
Because of -시-, it shows respect.

So the overall feeling is something like:

The teacher warmly greeted me/us, and I’m expressing that respectfully and appreciatively.