Koreans use it in class, meetings, or conversations when they want to ask something politely.
Yes. "질문 있어요 (jilmun isseoyo)" is polite and natural. You can also say "질문 있어 (jilmun isseo)" casually.
You can say "I have a question" — 질문이 있습니다 (jilmun-i isseumnida).
질문 있어요 means "I have a question." It's a polite way to get attention before asking something.
1. In class: When you don't understand lesson.
2. In meeting: To politely interrupt and clarify.
3. In conversation: Before asking something detailed.
Teacher, I have a question.
Excuse me, I have a question. (Formal)
I have a question about this part.
Hey, I have a question! (Casual)