Learn Hardcore Finnish: Minulla on idea.

It literally translates to "I have an idea." If you break it down word by word, it means "at me is idea," which shows how Finnish expresses possession.

What is the role of minulla in this sentence?

Minulla is the inessive (locative) form of minä (I). In Finnish, possession is indicated by placing the possessor in the inessive case rather than having a separate verb like "have" in English. It essentially means "at me" or "with me."

Why is the verb on used here, and how does it function?

On is the third person singular present form of olla (to be). In the sentence Minulla on idea, it links the possessor (minulla) with what is possessed (idea). Although it literally means "is," in this context it fulfills the role that "have" plays in English.

Why doesn’t the noun idea come with an article like a or the?

Finnish does not use articles. Whether a noun is interpreted as definite or indefinite is usually determined by context, so idea appears without an article.