hoeuiga ajik an kkeutnasseoyo.

Because 끝나다 is an intransitive verb meaning to end / to be over.
In this sentence, 회의 is the thing that is ending, so it is the subject:

• 회의가 끝났어요 = The meeting ended / The meeting is over

If you used 을/를, it would suggest that something is being acted on directly, but 끝나다 does not take a direct object.

A useful comparison:

• 회의가 끝났어요 = The meeting ended
• 회의를 끝냈어요 = (Someone) ended/finished the meeting

That second sentence uses 끝내다, which is transitive.

These two are a very common pair:

• 끝나다 = to end, to be finished, to be over
  
  • intransitive
• 끝내다 = to end something, to finish something
  
  • transitive

So:

• 회의가 끝났어요 = The meeting ended
• 회의를 끝냈어요 = Someone finished/ended the meeting

In your sentence, 회의가 아직 안 끝났어요, the idea is that the meeting itself is not over yet, so 끝나다 is the correct verb.

아직 usually means still or yet, depending on the sentence.

In a negative sentence like this one, it often means not yet:

• 아직 안 끝났어요 = hasn't ended yet

In a positive sentence, it often means still:

• 아직 끝나요 ❌ unnatural
• 아직이에요 = It's still not time / It's still the case
• 회의가 아직 진행 중이에요 = The meeting is still in progress

So in your sentence, 아직 adds the idea of yet.

안 is the short, common way to make a verb negative in Korean.

Pattern:

• 안 + verb

So:

• 끝났어요 = it ended / it is over
• 안 끝났어요 = it did not end / it isn't over

In this sentence:

• 회의가 아직 안 끝났어요 = The meeting hasn't ended yet

There is also a longer negative form using -지 않다:

• 회의가 아직 끝나지 않았어요

This means the same thing, but it sounds a little more formal or written than 안 끝났어요.

This is a very common point of confusion.

Korean often uses a past/result form to describe a present state that results from a completed action.

• 끝났어요 literally means ended
• but in context it often means is over / has ended

So:

• 안 끝났어요 can mean didn't end or hasn't ended
• with 아직, it naturally becomes hasn't ended yet

So even though English uses present wording like isn't over yet, Korean expresses it through the idea it has not ended yet.

Yes. Both are possible, but the nuance changes a little.

• 회의가 아직 안 끝났어요
  Focuses on the meeting as the subject. Neutral and straightforward.

• 회의는 아직 안 끝났어요
  Uses 는, which marks the topic and can add a slight contrast, like:
  As for the meeting, it hasn't ended yet.

For example, if you are comparing several things:

• 수업은 끝났는데 회의는 아직 안 끝났어요.
  The class ended, but the meeting hasn't ended yet.

So 가 is neutral subject marking, while 는 often gives topic or contrast.

Yes. It is in the polite informal style, often called 해요체.

Levels:

• 회의가 아직 안 끝났어요 = polite, everyday
• 회의가 아직 안 끝났습니다 = more formal
• 회의가 아직 안 끝났어 = casual, used with close friends or younger people

So the sentence you have is a very natural and useful everyday polite form.

They are not the same.

• 안 끝났어요 = it didn't end / it hasn't ended
• 못 끝났어요 = it couldn't end / it wasn't able to end

So 못 adds the idea of inability or impossibility.

For a meeting, 안 끝났어요 is the normal choice when you simply mean it is still going on.

• 회의가 아직 안 끝났어요 = The meeting hasn't ended yet

If you say:

• 회의가 아직 못 끝났어요

it sounds more like the meeting hasn't been able to finish yet, which is possible in some contexts but less neutral.

Yes, but the meaning changes slightly.

• 회의가 안 끝났어요 = The meeting didn't end / The meeting isn't over
• 회의가 아직 안 끝났어요 = The meeting hasn't ended yet

Without 아직, the sentence is still correct, but it loses the specific yet/still feeling.
If you want to clearly express not yet, keeping 아직 is best.

In natural speech, 끝났어요 is usually pronounced close to:

• 끈나써요

This happens because Korean pronunciation changes sounds across syllables.

A rough breakdown:

• 끝
  • 났어요
• the final consonant sound links and simplifies in fast speech
• so it sounds more like 끈나써요

You do not need to pronounce every written consonant separately the way an English speaker might expect.

It most directly means:

• The meeting hasn't ended yet

But in real conversation, it often implies:

• The meeting is still going on

So the sentence focuses on the fact that the meeting is not over yet, and from that, the listener naturally understands that it is probably still in progress.

The same pattern is very common with many events or activities.

Pattern:

• [noun] + 가/이 + 아직 안 끝났어요

Examples:

• 수업이 아직 안 끝났어요. = The class hasn't ended yet.
• 시험이 아직 안 끝났어요. = The exam hasn't ended yet.
• 일이 아직 안 끝났어요. = The work isn't finished yet.

So this sentence is a very useful model for everyday Korean.