Whose shoes are these? είναι σωστό.
Perfectly good sentence but the Greek did not include the word these. If you wanted an alternative, whose shoes are they, would be nearer to whose are the shoes .
Maybe noy
Not
Γιατί είναι λάθος το whose is the shoes
Πρέπει να συμφωνεί ο αριθμός του ρήματος με τον αριθμό του ουσιαστικού. Για παράδειγμα: -Whose is this pen? -Whose are these pens?
Σας ευχαριστώ