Searching library catalogs for a particular language may retrieve entries for films in which search term is not the primary language. Why?
Many library searches default to a a keyword search. As a result, the search retrieves any entries where a particular word appears, regardless of context. For example, a search for "Italian" will retrieve films about Italian-American families, in addition to films in the Italian language. Likewise, searching for a language will find catalog records where that language is one of the subtitle options. While a Portuguese language learner might wish to watch "Ghostbusters" with Portuguese subtitles, one doesn't typically classify "Ghostbusters" as a film in Portuguese.
You can browse lists of film by original language using the links accessible on the Language tab above. Click the "INFO" link in the last column to access the catalog record for the film.