naeil hoeuiga isseoseo iljjik ireonaya haeyo.

있어서 is the connective form of 있다.

• 있다 = to exist, to be, to have
• -어서 = and so / because / since

So 회의가 있어서 literally means something like because there is a meeting. In natural English, that becomes because I have a meeting or since there’s a meeting.

In this sentence, it connects the reason to the result:

• 회의가 있어서 = because I have a meeting
• 일찍 일어나야 해요 = I have to get up early

In Korean, 있다 often goes with 이/가 on the thing that exists.

So:

• 회의가 있다 = there is a meeting / I have a meeting

Here, 회의가 marks meeting as the thing that exists or is scheduled.

This can feel strange to English speakers because English says I have a meeting, with I as the subject. Korean often expresses it more like a meeting exists.

Korean often leaves out subjects when they are obvious from context.

So even though the sentence does not say 저는, the listener naturally understands that the speaker is talking about themself:

• 내일 회의가 있어서 일찍 일어나야 해요.
• Natural understanding: I have a meeting tomorrow, so I have to get up early.

You could add 저는 if needed:

• 저는 내일 회의가 있어서 일찍 일어나야 해요.

But in everyday Korean, leaving it out is very normal.

This comes from the verb 일어나다 = to get up / wake up.

The grammar is:

• -아/어야 하다 = have to / must

So:

• 일어나다 → 일어나야 하다
• polite form: 일어나야 해요

That whole part means have to get up.

A quick breakdown:

• 일어나- = get up
• -야 하다 = have to
• 해요 = polite present form of 하다

Usually it feels closer to have to or need to in everyday English.

• 일어나야 해요 = I have to get up early / I need to get up early

It can sometimes feel as strong as must, but in normal conversation it is often just the natural way to express necessity.

So for this sentence, have to get up early is the most natural interpretation.

일찍 is an adverb meaning early. In Korean, adverbs usually come before the verb they modify.

So:

• 일찍 일어나야 해요 = have to get up early

This is very normal word order in Korean:

• time / reason / adverb information first
• main verb later

해요 is the polite, conversational style. It is very common in everyday speech.

So 일어나야 해요 is polite and natural in most situations.

Compare:

• 일어나야 해. = casual, plain conversation
• 일어나야 해요. = polite everyday speech
• 일어나야 합니다. = more formal

This sentence uses a friendly, standard polite style.

Yes, but the nuance changes a little.

• 회의가 있어서 = because I have a meeting / since I have a meeting
  
  • very natural and common
• 회의가 있으니까 = because I have a meeting, you see / since I have a meeting
  
  • can sound a bit more direct or explanatory
• 회의 때문에 = because of the meeting
  
  • focuses more on the meeting as the cause

For this sentence, 회의가 있어서 sounds very natural and smooth.

Yes. Literally, 회의가 있다 is closer to there is a meeting.

But with events, appointments, classes, tests, and meetings, Korean often uses this pattern where English would say have.

For example:

• 수업이 있어요 = I have class / there is a class
• 시험이 있어요 = I have an exam / there is an exam
• 회의가 있어요 = I have a meeting / there is a meeting

So both ideas are built into the Korean expression, and the exact English translation depends on context.

Yes, Korean word order is flexible, especially with time expressions.

• 내일 회의가 있어서 일찍 일어나야 해요. = very natural
• 회의가 내일 있어서 일찍 일어나야 해요. = also possible, but less neutral
• 내일은 회의가 있어서 일찍 일어나야 해요. = adds topic/contrast, something like as for tomorrow

Putting 내일 at the beginning is the most straightforward and common choice here.