Is there an interrogative form of cuyo?
We can use cuyo to mean whose:
Ésos son los amigos en cuya casa nos hospedamos.
Those are the friends in whose house we spent the night.
Is there an interrogative form, like maybe cúyo? That is, could you say
¿En cúya casa se hospedaron ustedes?
In whose house did you spend the night?
or would you have to say
¿En la casa de quién/quiénes se hospedaron ustedes?
When it's a question of "whose" (as far as I've seen on Duolingo, not a native), De quién is what is used.
EDIT: Searched, and de quién/de quiénes are used in questions of "whose".