We now have support for browsing by country and language. As some films have multiple languages listed, browsing French-language films (https://letterboxd.com/films/language/french/ as an example) will show English-language films as well (where those films have portions of dialog in French). We’d like to improve this in the future to be able to show films whose principal language is French.
You can do this using the Find A Film box on the main Films page. We plan to improve search to make use of this too.
This will be added when we transition to TMDb’s v3 API.