Hi! I think that if you don't use subtitles at all, you risk them losing interest because it may get too difficult for them. I'd go for subtitles in English if you show them the whole film or even in Catalan/Spanish, but I'd make sure they were listening to the original soundtrack, so I'd show chunks of the film and have them do exercises on what they have seen and heard. This also depends on what your objectives are -if it's done as a listening exercise, then you have to focus on the listening...With more advanced classes ...no sweat, it can be English only and no subtitles if it's listening you want to practise. All the best.