jinandareneun gaseubiga saenggakboda jeokge nawaseo dahaengieosseo.

Last month, the gas bill was lower than I expected, so that was a relief.

Breakdown of jinandareneun gaseubiga saenggakboda jeokge nawaseo dahaengieosseo.

• ~는: topic particle
• ~가: subject particle
• ~에: time particle
• 나오다: to come out

Questions & Answers about jinandareneun gaseubiga saenggakboda jeokge nawaseo dahaengieosseo.

Why is 지난달에는 used instead of just 지난달에?

-에는 is 에 + 는.

• 에 marks the time: in/at
• 는 makes 지난달 the topic and often adds a slight contrast

So 지난달에는 feels like:

• as for last month
• last month, at least
• when it comes to last month

This can imply a comparison with other months, even if it is not stated directly.

• 지난달에 가스비가 적게 나왔어 = The gas bill was low last month.
• 지난달에는 가스비가 적게 나왔어 = As for last month, the gas bill was low.
  (Maybe other months were different.)

Why does 가스비 take 가?

Because in this sentence, 가스비 is the subject of 나오다.

Korean often uses 나오다 for things like:

• bills
• prices
• scores
• results

So the literal structure is close to:

• The gas bill came out low
• The amount of the gas bill came out lower than expected

That is why 가스비가 is natural here.

If you said 가스비는, you would be making gas bill the topic instead:

• 가스비는 생각보다 적게 나왔어
  = As for the gas bill, it came out lower than expected.

Both are possible, but 가스비가 fits the basic subject role very naturally.

What does 나오다 mean here? It usually means to come out, right?