Part of James Delaney's more mysterious antics in BBC's Taboo (2017) is his occasional employment of somewhat "foreign" rituals, together with speaking in a distinctly non-English language (e.g. at his father's funeral or during his interrogation in the Tower).
What I wonder is if those are traditions that he picked up during his 10 years in Africa or from his mother's heritage, who was a Nuu-chah-nulth (or "Nootka Indian") supposedly "bought" by his father over in America. While the language seems somewhat Native American to the ignorant ear, his mother was sent to the asylum when he was still very young and I'm not sure she could have exerted much of an influence on him.
Do we know what language he was speaking? Was it an existing language whose origin we can pinpoint, maybe even the genuine language of the Nuu-chah-nulth, or something entirely different he picked up during his absence? Or did the show's writers exert some creative freedom there?