: ...mind blown. I really want to find out now which language became Covenant
: speech. Surprised that the Internet hasn't stumbled on the answer yet.

It sounds like he means it's a conlang. We know 343 were involved in shaping some elements of the game, and have continued to expand the Sangheili lexicon - I would love it if we could someday treat Sangheili like we do Klingon or Mandalorian, constructing whole sentences on our own. And speaking of Mandalorian, Karen Traviss (touch wood, turn three times, throw salt and cross myself) worked on expanding that too, which seemed to go down a bit better than some other elements of her Star Wars stories did.