Which endangered languages do you like and why? Would you like to see them on Duolingo?
Wow, I didn't expect to see a person who's interested in these languages! It's very rare to see a person who's not from Russia and knows about Circassian, Ossetic and Chuvash. I doubt that these languages can be added on Duolingo, but I like them, too. And I hope one day we will see them on Duolingo or anywhere else. So sad there's not too many materials for learning them.
Navajo was used as a "cryptographic" language during WW2. Navajo is supposed to be so difficult that the US Army hired Navajo people to talk the radio, assuming the Japanese could never understand, which was true. As a person working in cryptograhpy, I'd love to learn Navajo. But then, I'd probably encounter the same issues the Japanese did.
Woman in line is talking on the phone in a foreign language. Man behind her gets irritated, and says
"Lady, we're in America here. If you want to speak Spanish, go to Mexico".
"Sir, I was speaking Navajo. If you want to speak English, go back to England".