When hotel owner Sig. Nicoletti tells the shoeshine boy to get out of his lobby, he speaks to him in English. In real life, surely they would automatically speak Italian to each other. Also, since all he's doing is shooing the boy out of the building, the (American) audience would know what he's saying in Italian just by his gestures and tone. This was the technique used when the Italian woman was monopolizing the hotel telephone as Lucy was waiting for her call - she spoke only in Italian, both in her telephone conversation and when speaking to Lucy.