Voted Best Answer
Jan 20, 2017 - 10:43 AM
"da" transforms the verb mangiare to a passive form. "che cosa vuole da mangiare" = "what do you want to be eaten". Those types of prepositions are very rare in english and very common in italian or french. I think the program should accept the "da mangiare" in this case. An italian expert may have a better in-depth explanation about that preposition.