sudoseneun jeongiseboda deol naojiman kkok hwaginhaeya haeyo.

는 is the topic particle. It marks 수도세 (water bill / water charges) as the thing being talked about.

In this sentence, 수도세는 feels like as for the water bill or when it comes to the water bill.

It can also create a slight contrast, especially because the sentence later compares it with 전기세 (electric bill).

보다 means than when making a comparison.

So:

• 전기세보다 = than the electric bill
• 수도세는 전기세보다 덜 나오지만 = the water bill comes out less than the electric bill, but...

This is a very common comparison pattern:

• A는 B보다 커요 = A is bigger than B
• 오늘은 어제보다 더워요 = Today is hotter than yesterday

덜 means less or not as much.

So:

• 더 = more
• 덜 = less

In this sentence:

• 덜 나오다 = to come out less / to be lower

Examples:

• 이번 달 전기세가 지난달보다 더 나왔어요.
  = This month’s electric bill came out higher than last month’s.
• 수도세가 생각보다 덜 나왔어요.
  = The water bill came out lower than I expected.

Yes, literally 나오다 often means to come out, but in Korean it is also commonly used for results, figures, bills, scores, and amounts appearing.

So with bills, 나오다 can mean:

• to be charged
• to come to
• to show up as
• to amount to

For example:

• 전기세가 많이 나왔어요.
  = The electric bill was high.
• 이번 달 요금이 적게 나왔어요.
  = This month’s fee came out low.

So 수도세는 전기세보다 덜 나오지만 is naturally understood as the water bill is lower than the electric bill, but...

-지만 is a grammar ending meaning but / although. It attaches directly to the verb stem.

• 나오다 → stem 나오-
• 나오지만 = comes out..., but

So:

• 덜 나오지만 = it comes out less, but...

Using 나와요 하지만 is grammatically possible in some situations, but it sounds less smooth here because Korean usually prefers connecting the clauses directly with -지만.

Compare:

• 비싸지만 좋아요. = It’s expensive, but it’s good.
• 비싸요. 하지만 좋아요. = It’s expensive. But it’s good.

The second version is more separated and emphatic.

It can be translated as either but or although, depending on context.

Here, -지만 connects two ideas:

• the water bill is lower than the electric bill
• even so, you must check it

So the feeling is:

• ..., but you still have to check it
• ..., although it’s lower, you still have to check it

In natural English, but is probably the most straightforward translation here.

꼭 means definitely, certainly, for sure, or without fail.

It adds a sense of importance or necessity.

So:

• 확인해야 해요 = you have to check
• 꼭 확인해야 해요 = you definitely have to check

It is very common in advice, reminders, and instructions:

• 꼭 오세요. = Please be sure to come.
• 약은 꼭 먹어야 해요. = You really need to take the medicine.

This comes from the grammar pattern -아/어야 하다, which means must / have to / need to.

Breakdown:

• 확인하다 = to check / confirm
• 확인해야 하다 = have to check
• 확인해야 해요 = polite spoken form of have to check

So:

• 가야 해요 = have to go
• 먹어야 해요 = have to eat
• 확인해야 해요 = have to check

This is one of the most important Korean grammar patterns.

Korean often leaves the subject unstated when it is understood from context.

So 꼭 확인해야 해요 could mean:

• you have to check
• we have to check
• one must check
• sometimes even I have to check

In a sentence like this, it most naturally sounds like you have to check it or you should definitely check it, especially if someone is giving advice.

The object is omitted because it is already understood from context.

The sentence is talking about 수도세 (the water bill), so 확인해야 해요 naturally means:

• you have to check the water bill
• you have to make sure to check it

Korean often drops objects when they are obvious.

If you wanted to say it more explicitly, you could say:

• 수도세를 꼭 확인해야 해요.
  = You definitely have to check the water bill.

Usually, yes. 수도세 refers to charges related to water service, so water bill is the normal English translation.

Breakdown:

• 수도 = waterworks / tap water / water service
• 세 = tax, fee, charge

In everyday Korean, words ending in -세 often refer to bills or charges, even if the literal meaning may involve tax/fee.

For example:

• 전기세 = electric bill
• 가스비 = gas bill
  (here 비 is used instead of 세)

In casual use, 수도세 is a very natural household-bill word.

Yes, 전기세 is very common in everyday speech.

However, you may also see more formal or official expressions like:

• 전기 요금 = electricity charge / electric bill

In daily conversation, 전기세 sounds natural and familiar.

Similarly:

• 수도 요금 can also be used instead of 수도세

So there may be slight differences in formality, but the general meaning is clear.

Yes, it gives that impression in this specific context.

The speaker is saying:

• the water bill is lower than the electric bill,
• but it still needs to be checked.

So the nuance is something like:

Even though the water bill is usually not as high as the electric bill, you shouldn’t ignore it.

The important part is the contrast created by -지만: lower cost does not mean unimportant.

Yes, that is a good basic translation.

A slightly more natural English version might be:

• The water bill is lower than the electric bill, but you still need to check it.
• Water bills are usually lower than electricity bills, but you should definitely check them.

The reason for adjusting the English is that 나오다 with bills often means comes out to / ends up being / is charged as, so is less is understandable, but is lower often sounds more natural in English.