Learn Hardcore Finnish: Anteeksi, minulla on kysymys.

Anteeksi is a polite way to say excuse me or sorry in order to get someone’s attention or apologize briefly. On the other hand, olen pahoillani means I am sorry in a more personal sense, typically used for expressing regret about something you’ve done. In this context, you just want to politely grab attention, so anteeksi is more appropriate.

Why is the verb "to have" translated as minulla on instead of a direct equivalent like minä omistan?

In Finnish, possession is often expressed with the construction minulla on, which literally translates to on me there is. It can mean I have. Meanwhile, minä omistan tends to mean I own and is used less frequently in everyday expressions of having something.

Why do we say kysymys in its basic nominative form instead of another case?

Since you are simply stating that you have a question in general, the noun remains in its nominative form kysymys (question). If you were referring to, for example, one question out of many, you might use a partitive form kuten kysymystä in a larger context, but here the basic form emphasizes just the existence of a question.

Which part of the sentence literally means "excuse me, I have a question"?