Is it possible to have separate library based on language?

[TheDreadPirate]

Are you asking about the metadata for the library or what audio track is played by default?. Showing library metadata in a particular language requires creating a separate library and changing the language in the library settings to your language of choice. Settings > Dashboard > Library > Add new library > Set "Preferred download language" to your language of choice, configure rest of library settings as you normally would. You can go one step farther and create a separate account for your family and only give them access to the libraries in their language.

If you only care about the audio track played by default, you don't need a separate library. You have to change the client settings to prefer your language's audio track. Settings > Playback > Audio settings > Preferred audio language.