Standard English subtitles for Game of Thrones often mark non-English dialogue as [speaking Dothraki] or [speaking High Valyrian] without providing a translation. For Season 3, where Daenerys’s slave interactions and some Tywin scenes include foreign language parts, this can leave you lost.
If your media player is missing these translations, you can download external .srt files from several community-vetted sources: Standard English subtitles for Game of Thrones often
: One of the largest repositories. Search for "Game of Thrones S03" and look for entries explicitly tagged as "English (forced)". Standard English subtitles for Game of Thrones often