hacheon yeopeseo yuri jogageul chajassseupnida.

하천 is a somewhat formal/general word meaning stream, river, or waterway.

• 강 usually means a river and often sounds larger/more specific.
• 개울 usually means a small stream or brook.
• 하천 is broader and can sound a bit more official, like something you might see in writing, reports, or signs.

So in this sentence, 하천 옆에서 means by the stream/river or next to the waterway.

This is a very common question.

• 옆에 means at / next to / beside
• 옆에서 means at / next to / beside, but with emphasis on the place where an action happens

Because 찾았습니다 is an action (found), Korean often uses 에서 to mark the location where that action took place.

So:

• 하천 옆에 = next to the stream
• 하천 옆에서 유리 조각을 찾았습니다 = I found glass pieces next to the stream

If you used 옆에, it would sound less natural here, because 찾다 is an action happening at that location.

In this sentence, 에서 marks the location of an action.

Compare:

• 학교에 가요 = I go to school
• 학교에서 공부해요 = I study at school

Here:

• 하천 옆에서 = at/by the side of the stream, where the action of finding happened

So 에서 answers the question where did you find it?

조각 means piece, fragment, or shard.

So:

• 유리 = glass
• 유리 조각 = a piece of glass / glass fragment / glass shard

If you just said 유리를 찾았습니다, that would usually mean I found glass in a more general sense.
But 유리 조각 is more specific: it means broken pieces or shards of glass.

That makes the image much clearer.

을/를 is the object particle. It marks what was found.

• 유리 조각을 찾았습니다
  • 유리 조각 = glass shard(s)
  • 을 = object marker
  • 찾았습니다 = found

So it shows that glass shard(s) are the thing affected by the verb.

Because 유리 조각 ends in a consonant, it takes 을 rather than 를.

찾았습니다 is:

• past tense
• formal polite style (also called 합니다-style)

It comes from 찾다 (to find / to look for) → 찾았습니다 (found).

This style is common in:

• formal speech
• presentations
• news-style narration
• polite writing
• speaking to someone respectfully in a formal setting

In everyday conversation, you would more often hear:

• 찾았어요 = polite but less formal
• 찾았어 = casual

찾다 can mean both:

• to look for
• to find

The meaning depends on context.

In this sentence, because it is past tense and the meaning is already given, 찾았습니다 is understood as found.

Compare:

• 유리 조각을 찾고 있습니다 = I am looking for glass shards
• 유리 조각을 찾았습니다 = I found glass shards

So the tense and context help you decide which meaning is intended.

Korean very often leaves out the subject when it is already understood from context.

So:

• 하천 옆에서 유리 조각을 찾았습니다 naturally means something like
  I found glass shards by the stream
  or
  We found glass shards by the stream

The subject does not need to be stated unless it is important for clarity or emphasis.

If you wanted to include it, you could say:

• 제가 하천 옆에서 유리 조각을 찾았습니다 = I found glass shards by the stream

But in many situations, that would sound unnecessary.

Korean word order is more flexible than English, because particles show each word’s role.

The most neutral order here is:

• 하천 옆에서 유리 조각을 찾았습니다

But you could also say:

• 유리 조각을 하천 옆에서 찾았습니다

This puts a little more focus on 유리 조각을.

In general, Korean often places the verb at the end, but other parts can move around for emphasis, topic, or style.

It can mean a piece of glass or pieces of glass, depending on context.

Korean often does not mark singular vs. plural as clearly as English does.

So:

• 유리 조각을 찾았습니다 could mean
  I found a glass shard
  or
  I found glass shards

If you want to make it clearly plural, you could say:

• 유리 조각들을 찾았습니다

But in many cases, Korean simply leaves it unmarked.

Yes, it is natural and grammatically correct.

It sounds like a clear written or spoken statement, especially in a slightly formal tone because of 찾았습니다.

A more conversational version would be:

• 하천 옆에서 유리 조각을 찾았어요

That means the same thing, but sounds more like everyday polite speech.