"Whose pens are these?"
Translation:De quem são estas canetas?
No. Inspite the mouseover shows "cujos" as a possible translation, it doesnt work here. When whose works as a relative pronoun it is translated as "cujo, cujos, cuja, cujas". The girl whose bike was red... = a garota cujA biciletA era vermelha... / the woman whose clothes... a mulher cujAS roupAS / the boy whose toy.... o menino cujO brinquedO... and so on ;)