심각한 문제가

a serious problem

→ 심각하다
phrase Rare #31,787
a serious problem The particle 가 marks the problem as the subject of the sentence.
KO: 심각한 문제가 생겼어요.
EN: A serious problem came up.

그런데 심각한 문제가 아니었나 봅니다

But I guess it wasn't a serious problem after all.

— 콘클라베 (2024)

한 가지 심각한 문제가 또 있습니다 됩니까?

There’s another serious problem. Is that okay?

— Pandora (2016)