In general, films in the original language and versions with subtitles in a range of different languages are both widely available in Europe. If the main aim of subtitles is allowing viewers to understand dialogue in films where they don’t know the language, subtitles are also being seen to an ever-greater extent through an educational lens.
Clearly, watching a film in a foreign language that you’re studying is a good way to pick up vocabulary in that language.
Nevertheless, depending on our learning level and abilities in the language of the film, the impact of subtitles on our understanding varies quite considerably. So, with that film you want to watch: with or without subtitles?