Situation: You have knocked at the door of Maria's house but nobody has answered. Since the door is open, you go inside, but she is not immediately visible in the entrance hall. You think that she might be in the next room. Call out her name.

Interpretation of the utterance: Vocative, followed by a Wh-question

Informator: M. P. B.

Utterance: Maria, a on ès?

Translation: Maria, where are you?
[Maria, at where be(present, 2nd sing.)?]