nelli teotl = true god -- Isabel Laack points out that this is a term coined by the missionaries to express a Christian monotheistic concept in Nahuatl.
Isabel Laack, Aztec Religion and Art of Writing (Leiden: Brill, 2019), 116.
y ça ce huellnelli dios = yet indeed one true God (San Bartolomé Atenco, 1617)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 3, 58–59.
amo nelli ỹ ca ye tlapic = It is not true; it is made up (early seventeenth century, central New Spain)
Annals of His Time: Don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, James Lockhart, Susan Schroeder, and Doris Namala, eds. and transl. (Stanford: Stanford University Press, 2006), 66–67.
nelli mach = in truth, really all (an extreme intensifier)
Robert Haskett and Stephanie Wood's notes from Nahuatl sessions with James Lockhart and subsequent research.