The Mayan languages stopped being written, but not spoken, by their language community as a result of the Spanish conquest: https://en.wikipedia.org/wiki/Mayan

The Mayan languages stopped being written, but not spoken, by their language community as a result of the Spanish conquest: https://en.wikipedia.org/wiki/Mayan_languages#Writing_systems https://en.wikipedia.org/wiki/Mayan_languages#Writing_system... In particular, this was an effort to suppress Maya religion that led to an almost complete loss of knowledge of the original writing system. Later on Maya started being written with Latin characters, but there are still lots of native speakers who are functionally literate in Spanish but not in Maya.