Ipai language

Ipai, also known as 'Iipay or Northern Diegueño, is the Native American language spoken by the Kumeyaay people of central San Diego County, California. Hinton (1994:28) suggested a conservative estimate of 25 surviving Ipai speakers.
Ipai belongs to the Yuman language family and to the Delta–California branch of that family. Ipai and its neighbors to the south, Kumeyaay and Tipai, were often considered to be dialects of a single Diegueño language, but the current consensus among linguists seem to be that at least three distinct languages are present within the dialect chain (e.g., Langdon 1990). Confusingly, Kumeyaay is commonly used as a designation both for the central language in this family and for the Ipai-Kumeyaay-Tipai people as a whole.
Published documentation for the Ipai language includes reference and teaching grammars, a dictionary, and several texts (cf. Mithun 1999:578).