The US Census Bureau's American Community Survey annually asks more than 1 million Americans questions about their lives, families, and backgrounds. One question asks respondents what language they mainly speak in their homes.

Over the years, the children of fluent speakers were only learning and speaking English. Teachers in the program were not using it in the classroom because they weren’t fluent speakers themselves and that’s where children were spending most of their day. 

In fact, the most recent Program Information Report data shows that less than 3 percent of Head Start children in tribal programs nationwide spoke their native language. 

In this program’s efforts to revitalize their tribal language, the committee reviewed current research on language revitalization and preservation, as well as literature on teaching children who have dual languages. 

They learned that approximately half of the 7,000 languages spoken in the world today are expected to lose their last speaker by the end of this century.

https://eclkc.ohs.acf.hhs.gov/publication/tribal-language-preservation-revitalization