In many languages a raising inflection at the end of a statement makes it into a question. A post I read the other day on Invading Holland discusses the authors’ struggles with the Dutch language. Particularly the way he adds a raising inflection to the ends of statements, not because he want to make them into questions, but because he’s unsure if he’s saying them correctly and seeks confirmation.
This is often misinterpreted because rather than answering the unspoken question, i.e. “Did I get that right?”, people tend to doubt his sanity when he appears to ask them questions like “I’ll have a coffee?” or “I’d like to go to the station?”. He calls it the ‘The Unintentional Question Effect’.
When speaking foreign, I’ve also been known to unleash unintended questions on unsuspecting interlocutors, and have noticed others doing the same thing.