sanchaekroneun kkaekkeushan banmyeon hacheoneun ajik oyeomdoeeo issseupnida.

반면 means on the other hand, whereas, or in contrast. It connects two clauses that are being compared or contrasted.

In this sentence:

• 산책로는 깨끗한 반면
• 하천은 아직 오염되어 있습니다

the speaker is contrasting the two places:

• the walking path is clean
• the stream is still polluted

So A-(으)ㄴ 반면 B is a very common pattern meaning while A is..., B is... or whereas A..., B....

This is because 반면 commonly attaches to a modifier form before it.

For descriptive verbs/adjectives, you usually use:

• A-(으)ㄴ 반면

So:

• 깨끗하다 → dictionary form
• 깨끗한 → modifying form
• 깨끗한 반면 → while it is clean / whereas it is clean

This is just the normal grammar pattern.
Other examples:

• 조용한 반면 시끄러운 곳도 있다 = While some places are quiet, others are noisy.
• 빠른 반면 불안정하다 = It is fast, but on the other hand it is unstable.

The particle 는 is doing more than just marking the topic here; it also helps create a contrast.

• 산책로는 = as for the walking path
• 하천은 = as for the stream

Using 는 on both nouns highlights the comparison between them. It has a similar effect to saying:

• The walking path, on the other hand, is clean
• The stream, however, is still polluted

So in this sentence, 는 helps support the contrast already expressed by 반면.

산책로 means a walking path, walkway, or trail for walking.

It is made of:

• 산책 = walk, stroll
• 로 = road, route, path

So it refers to a path designed or used for walking, often in parks, along rivers, or in residential areas.

하천 is a somewhat more general or formal word for a stream, waterway, or river channel.

Roughly:

• 강 = river
• 개울 = brook / small stream
• 하천 = watercourse / stream / riverway, often used in formal, environmental, or administrative contexts

In a sentence about cleanliness or pollution, 하천 sounds very natural because it is often used in discussions about the environment.

아직 means still or yet, depending on the sentence.

Here it means still:

• 하천은 아직 오염되어 있습니다
• The stream is still polluted

It comes before the verb phrase because adverbs in Korean usually go before what they modify.

Compare:

• 아직 멀었어요 = It is still far.
• 아직 안 왔어요 = He/She hasn’t come yet.

In this sentence, 아직 emphasizes that the pollution continues up to the present time.

오염되어 있습니다 describes a resulting state: something is in a polluted condition.

Breakdown:

• 오염 = pollution/contamination
• 오염되다 = to become polluted / to be polluted
• 오염되어 있다 = to be in a polluted state
• 오염되어 있습니다 = formal polite version

So this is not just talking about the action of becoming polluted; it focuses on the current condition.

A helpful way to think about it:

• 오염됐습니다 = it became polluted / it got polluted
• 오염되어 있습니다 = it is polluted (and remains in that state)

In many contexts, the English translation for both may simply be is polluted, but -어 있다 gives a stronger sense of the current state.

You could say 오염됐습니다, and it would be understandable. But there is a nuance difference.

• 오염됐습니다 can sound more like it became polluted or it has gotten polluted
• 오염되어 있습니다 emphasizes the present state: it is currently polluted

Since this sentence contrasts the present condition of two places:

• the trail is clean
• the stream is still polluted

오염되어 있습니다 fits very well.

Sometimes yes, but not with exactly the same nuance.

Compare:

• 산책로는 깨끗한 반면 하천은 아직 오염되어 있습니다.
• 산책로는 깨끗하지만 하천은 아직 오염되어 있습니다.

Both mean something like The walking path is clean, but the stream is still polluted.

The difference:

• 반면 sounds more like a structured comparison/contrast
• 하지만 sounds more like a general but/however

So 반면 is especially good when placing two things side by side and comparing them directly.

Yes. 있습니다 is the formal polite style, often used in:

• reports
• announcements
• presentations
• news
• formal writing

The same sentence in a less formal polite style would be:

• 산책로는 깨끗한 반면 하천은 아직 오염되어 있어요.

And in a more casual style:

• 산책로는 깨끗한 반면 하천은 아직 오염되어 있어.

Yes. Korean often presents the first clause and then adds the contrasting second clause, with the main verb coming at the end of each clause or final sentence.

Literal structure:

• 산책로는 = as for the walking path
• 깨끗한 반면 = while it is clean / whereas it is clean
• 하천은 = as for the stream
• 아직 = still
• 오염되어 있습니다 = is polluted

A very literal English-style unpacking would be:

As for the walking path, while it is clean, as for the stream, it is still polluted.

Natural English smooths this out to:

While the walking path is clean, the stream is still polluted.

Yes, very much so. The word 아직 strongly suggests that the situation has not improved fully yet.

So the sentence does more than just describe two places. It also implies:

• one area has already become clean
• the other area has not been fully fixed yet

That makes it sound very natural in discussions about environmental cleanup, public facilities, or local conditions.