Principal English Translation:
for, because, since; that's the way it is
Alonso de Molina:
Canel. pues es asi, o pues asi es. aduerbio.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, f. 12v.
Frances Karttunen:
CANEL since / pues es asi, o pues asi es (M) This contrasts with CĀNNEL ‘where?’. See CA, NEL.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 24.
Horacio Carochi / English:
ca nel = for, because
Horacio Carochi, S.J., Grammar of the Mexican language with an explanation of its adverbs (1645), translated and edited with commentary by James Lockhart, UCLA Latin American Studies Volume 89 (Stanford: Stanford University Press, UCLA Latin American Center Publications, 2001), 499.
Lockhart’s Nahuatl as Written:
canel, particle. because, for, since (giving the reason for something). ca, nel secondary particle from nelli.
James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 213.
Attestations from sources in English:
Carochi says that when ca comes before nel it becomes a causal adverb. Lockhart adds that ca nel is ubiquitous, and that even by itself ca often indicates causality. He adds, "Nel is a particle reduced from nelli, a true thing, but it has evolved to the point of rarely having much to do with truth per se; it is usually found in particle combinations."
Horacio Carochi, S.J., Grammar of the Mexican language with an explanation of its adverbs (1645), translated and edited with commentary by James Lockhart, UCLA Latin American Studies Volume 89 (Stanford: Stanford University Press, UCLA Latin American Center Publications, 2001), 405–406.