gugeupchaga gyotongsago hyeonjange got dochakhaesseoyo.

가 marks 구급차 as the grammatical subject, the thing that did the arriving.

Using 는 would add a topic or contrast nuance:

• 구급차가 ... 도착했어요 = The ambulance arrived.
• 구급차는 ... 도착했어요 = As for the ambulance, it arrived. / The ambulance, at least, arrived.

In a neutral statement about what happened, 가 is very natural.

Because 교통사고 현장 is a noun + noun combination.

Here, 교통사고 directly modifies 현장, so the whole phrase means traffic-accident scene or the scene of a traffic accident.

This is very common in Korean:

• 학교 건물 = school building
• 회사 사람 = company person / coworker
• 교통사고 현장 = traffic accident scene

So 교통사고 is not acting as a separate noun with its own particle here.

Because 도착하다 uses 에 to mark the destination.

• 에 = to, at, toward a destination or location
• 에서 = at, in, from the place where an action happens

Since 도착하다 means to arrive, the place is the endpoint of movement, so 에 is correct:

• 현장에 도착했어요 = arrived at the scene

If you used 에서, it would sound like the scene is the place where some other action happened:

• 현장에서 기다렸어요 = waited at the scene

No. 도착하다 is an intransitive verb, so it does not take a direct object.

That means you do not arrive something. You arrive at a place.

So this is correct:

• 현장에 도착했어요

But this would be wrong:

• 현장을 도착했어요

It works a lot like English arrive, which also normally does not take a direct object.

곧 means soon, shortly, or before long.

It is an adverb, and it usually goes before the verb or verb phrase:

• 곧 도착했어요 = arrived soon / shortly arrived

It does not by itself make the sentence future tense. It just adds the idea of not much time passing.

Because 곧 does not have to refer to the future.

In English, soon often suggests the future, but it can also describe something that happened shortly afterward:

• The ambulance soon arrived.

That is what Korean is doing here.
So 곧 도착했어요 means the ambulance arrived shortly afterward.

If you wanted a clear future meaning, you would usually say something like:

• 구급차가 교통사고 현장에 곧 도착할 거예요 = The ambulance will arrive at the traffic accident scene soon.

It comes from the dictionary form 도착하다, meaning to arrive.

Breakdown:

• 도착하다 = to arrive
• 도착하- = verb stem
• past tense of 하다 becomes 했-
• -어요 = polite ending

So:

• 도착하다
• 도착했어요

This is the standard polite past form.

Not completely. Korean word order is fairly flexible because particles show each word’s role.

The given order is very natural:

• 구급차가 교통사고 현장에 곧 도착했어요

But other orders can also work, depending on emphasis:

• 구급차가 곧 교통사고 현장에 도착했어요
• 교통사고 현장에 구급차가 곧 도착했어요

Even though several orders are possible, adverbs like 곧 are often placed near the verb.

It is the polite everyday style, often called the -어요 style.

It is appropriate in many normal conversations and neutral statements.

Compare:

• 도착했어요 = polite everyday
• 도착했습니다 = more formal
• 도착했어 = casual, used with close friends or younger people

So this sentence sounds polite but not stiff.

현장 means scene or site, especially the actual place where an event, accident, or operation is happening.

장소 is a more general word for place or location.

So for a traffic accident, 현장 is much more natural:

• 교통사고 현장 = the accident scene
• 교통사고 장소 would sound more general and less idiomatic

In emergency or news-related contexts, 현장 is the usual word.

Yes. Korean often omits information that is already clear from context.

For example, if everyone already knows you are talking about the ambulance and the accident scene, a speaker might simply say:

• 곧 도착했어요
• 현장에 곧 도착했어요

However, the full sentence is useful when the speaker wants to be clear and explicit.