nuguege gyotongsagoreul singohaesseoyo?

누구에게 means to whom or to who in the sense of the person who received the report.

• 누구 = who
• 에게 = to, toward, for (used mainly with people/animate beings)

So 누구에게 is asking about the recipient of the action 신고하다 (to report).

Because 누구 is not the thing being reported. It is the person you reported it to.

In this sentence:

• 교통사고를 = the traffic accident (object of 신고하다)
• 누구에게 = to whom (recipient/target person)

So the structure is basically:

• [thing reported] + 를/을
• [person reported to] + 에게/한테
• 신고하다

If you used 누구를, it would sound like who did you report?, which is a completely different meaning.

Because 교통사고 is the thing that was reported.

• 교통사고 = traffic accident
• 교통사고를 신고하다 = to report a traffic accident

The particle 를 marks the direct object.

So the sentence literally works like:

To whom did you report the traffic accident?

Not quite. 신고하다 usually means to report in a formal or official sense.

It is often used for things like:

• reporting an accident
• reporting a crime
• reporting a problem to authorities
• filing a report

So it is stronger and more formal than just telling someone.

Examples:

• 경찰에 신고하다 = to report to the police
• 분실물을 신고하다 = to report a lost item

신고했어요 is the past form of 신고해요.

• 신고하다 = dictionary form
• 신고해요 = present polite
• 신고했어요 = past polite

In Korean, this past form is used for a completed action. Depending on context, it can correspond to English:

• did you report...?
• have you reported...?

So Korean past tense often covers both a simple past meaning and a present-relevance meaning.

It is in the polite informal style, often called the -어요/-아요 style.

That means it is:

• polite enough for everyday conversation
• natural in most normal situations
• less formal than 신고했습니다
• more polite than 신고했어

Comparison:

• 신고했어요? = polite, everyday
• 신고했습니까? / 신고했어요? = more formal / standard questioning styles
• 신고했어? = casual, used with close friends or younger people

Yes. 누구한테 교통사고를 신고했어요? is very natural in conversation.

Difference:

• 에게 = a bit more neutral or slightly more formal/written
• 한테 = common in spoken Korean, casual-neutral
• 께 = honorific, used for someone who deserves respect

Examples:

• 누구에게 신고했어요? = to whom did you report it?
• 누구한테 신고했어요? = same meaning, more conversational
• 누구께 신고했어요? = would only be used in special honorific situations

Yes. Korean word order is flexible as long as the particles are clear.

You can say:

• 누구에게 교통사고를 신고했어요?
• 교통사고를 누구에게 신고했어요?

Both mean the same thing.

The difference is mostly in focus:

• starting with 누구에게 puts more attention on the person
• starting with 교통사고를 puts more attention on the accident

Because Korean uses particles like 에게 and 를, the grammatical roles stay clear even when the order changes.

Korean often omits the subject when it is obvious from context.

In English, you usually need to say:

• Who did you report the traffic accident to?

In Korean, the you is usually understood, so it is not said unless needed for emphasis.

If you really wanted to include it, you could say:

• 당신은 누구에게 교통사고를 신고했어요?

But 당신 is often unnatural in ordinary conversation, so leaving the subject out is much more normal.

Yes, 에게 is mainly used with a person or animate recipient.

But in real Korean, when reporting something to an organization or institution, people very often use 에 instead:

• 경찰에 신고했어요 = I reported it to the police
• 보험회사에 신고했어요 = I reported it to the insurance company

So if you are asking specifically which person, 누구에게 is natural. If you are asking more generally to what place/organization, Korean often uses 어디에 or names the organization with 에.

For example:

• 어디에 신고했어요? = Where did you report it?

Yes, grammatically it is natural. But in real life, speakers might choose slightly different wording depending on the situation.

For example:

• 교통사고를 어디에 신고했어요? = Where did you report the traffic accident?
• 경찰에 신고했어요? = Did you report it to the police?
• 누구한테 교통사고 난 걸 알렸어요? = Who did you inform that there was a traffic accident?

Your sentence sounds like the speaker specifically wants to know which person or authority the accident was reported to.

It is pronounced roughly like 신고해써요.

That is because:

• 신고하다 becomes 신고했어요 in the past
• the written 했 is commonly heard like 핻/해ㅆ
• in smooth speech, learners often notice it sounds close to 해써요

A simple pronunciation guide:

• 누구에게 → nu-gu-e-ge
• 교통사고를 → gyo-tong-sa-go-reul
• 신고했어요 → sin-go-hae-sseo-yo

You do not need to pronounce every syllable in a stiff way; natural Korean speech will connect them smoothly.

Yes, if the context is already clear.

• 교통사고를 신고했어요 = reported the traffic accident
• 사고를 신고했어요 = reported the accident

교통사고 is more specific, while 사고 can mean accident more generally.

So using 교통사고 helps remove ambiguity and makes the sentence more precise.