nuga beonhopaneul jjigeosseoyo?

누가 is the normal form of 누구 + -가.

• 누구 = who
• -가 = subject marker

When 누구 takes -가, it usually becomes 누가 in natural Korean.

So:

• 누가 왔어요? = Who came?
• 누가 번호판을 찍었어요? = Who took a picture of the license plate?

You can think of 누가 as the standard subject form of who.

번호판 means license plate or number plate.

It is made of:

• 번호 = number
• 판 = plate/board

So literally it is something like number plate. In everyday Korean, this usually refers to a vehicle’s license plate.

The -을 is the object marker.

• 번호판 = license plate
• 번호판을 = the license plate (as the thing being acted on)

In this sentence, the verb is 찍었어요, so 번호판 is the thing that was photographed.

So the structure is:

• 누가 = who (subject)
• 번호판을 = the license plate (object)
• 찍었어요 = took a picture / photographed

Here, 찍었어요 means took a picture of or photographed.

The dictionary form is 찍다. This verb has several meanings depending on context, including:

• to stamp
• to 찍다 with a finger or tool
• to choose/pick
• to film
• to take a picture

In this sentence, because the object is 번호판, the natural meaning is photographed the license plate.

So 번호판을 찍었어요 means (someone) took a picture of the license plate.

Korean often says X을/를 찍다 to mean take a picture of X.

So both ideas are possible:

• 사진을 찍다 = to take a photo
• 번호판을 찍다 = to photograph the license plate

In English, we often say take a picture of the license plate.
In Korean, it is very natural to say just 번호판을 찍다, without explicitly adding 사진.

Yes.

• 찍다 = to take a picture / photograph
• 찍었어요 = took a picture / photographed

The -었- shows past tense, and -어요 makes it polite.

So the sentence is asking about something that already happened:

Who took a picture of the license plate?

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

• 찍었어요 is polite and very common in everyday conversation.
• It is appropriate in many normal situations: with strangers, coworkers, classmates, etc.

It is not:

• very casual like 찍었어?
• very formal like 찍었습니까?

So it sounds natural and respectful without being stiff.

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

For example, these are both possible:

• 누가 번호판을 찍었어요?
• 번호판을 누가 찍었어요?

Both mean essentially the same thing: Who took a picture of the license plate?

The difference is mostly about emphasis:

• 누가 번호판을 찍었어요? puts who first
• 번호판을 누가 찍었어요? brings the license plate to the front for focus/topic-like emphasis

By itself, 찍다 can have different meanings, so yes, the verb is flexible in Korean.

But in this sentence, the most natural interpretation is to take a picture of.

That is because:

• 번호판 is something people commonly photograph
• 누가 번호판을 찍었어요? strongly suggests a photo-related situation

If the context were different, another meaning might be possible, but without special context, learners should understand this as Who photographed the license plate?

Because 누가 itself is the subject.

In Korean, 누가 means who and already fills the subject role:

• 누가 = who (as the subject)

So the sentence structure is complete without any other subject noun.

Korean often leaves out information that is obvious, but here the subject is not omitted at all—the unknown subject is exactly what the question is asking about.

It would sound unnatural in standard Korean.

Native speakers normally say:

• 누가

not

• 누구가

So this is not just a casual shortening you can ignore; it is the expected form learners should use.

A good habit is to memorize:

• 누가 = who + subject marker
• 누구를 = whom / who + object marker
• 누구의 = whose / who’s

That will help you avoid trying to build every form from 누구 mechanically.