These languages are classified in three groups: Apart from Comanche, each of these groups contains one language spoken in a small area in the southern Sierra Nevada and valleys to the east (Mono, Timbisha, and Kawaiisu), and one language spoken in a much larger area extending to the north and east (Northern Paiute, Shoshoni, and Colorado River).

Some linguists have taken this pattern as an indication that Numic speaking peoples expanded quite recently from a small core, perhaps near the Owens Valley, into their current range.

[24] The anthropologist Peter N. Jones thinks this evidence to be of a circumstantial nature,[25] but this is a distinctly minority opinion among specialists in Numic.

Proto-Southern Numic preserved the Proto-Numic consonant system fairly intact, but the individual languages have undergone several changes.

Proto-Western Numic changed the nasal-stop clusters of Proto-Numic into voiced geminate stops.

In Mono and all dialects of Northern Paiute except Southern Nevada, these voiced geminate stops have become voiceless.

The following table shows some sample Numic cognate sets that illustrate the above changes.