"When do you want to go shopping?"
Translation:¿Cuándo quieres ir de compras?
I wrote ¿Cuándo quieres ir a comprar?, this was marked wrong. I found there is subtle difference between ir a comprar and ir de compras. the former means, go to buy (sth), the latter means go shopping (not necessarily to buy anything, can be window shopping).
ir de and ir a have subtle difference. Please check my comments above. This is one example why Spanish frustrates me. We are powerless in making rules. we are but only followers.
"cuando quiere usted ir de compras" marked wrong. Why? There is nothing indicating a familiar form must be used.
yes, I put the same answer... nothing to say familiar form necessary, you could be asking a customer in a formal situation, like a hotel clerk to a guest for example.