Ghanima is fluent in multiple languages, thanks to the people in her head. So far, Ancient Greek, Sumerian, Old Norse, Latin, Arabic, Romani, Gaelic, and French are the ones that have been stated in either book or FH canon, but odds are she knows more.

She also speaks fluent Galach, 'Standard' (English), Chakobsa (Fremen), and ASL, all from her own experiences.