The Nahuan or Aztecan languages are those languages of the Uto-Aztecan language family that have undergone the sound change known as Whorf's Law changing the original /*t/ to [tɬ] before */a/. Subsequently some Nahuan languages have changed /tl/ back to /t/ or to /l/, but it can still be seen that the language went through a -tl stage.
- Whorf, Benjamin Lee (1937). "The origin of Aztec tl". American Anthropologist 39: 265–274.
- Campbell, Lyle; and Ronald Langacker (1978). "Proto-Aztecan vowels: Part I". International Journal of American Linguistics (Chicago: University of Chicago Press) 44 (2): 85–102. doi:10.1086/465526. OCLC 1753556.