intla.

Headword: 
intla.
Principal English Translation: 

if, for that, when, however (a conditional conjunction; see Molina)

Orthographic Variants: 
yntla, ytla
IPAspelling: 
intɬɑː
Alonso de Molina: 

Intla. si. Conjunction condicional.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, f. 39r.

Frances Karttunen: 

INTLĀ if / si, conjuntión condicional (M) There are two homophonous particles, TLĀ ‘let it be so that’ (synonymous with MĀ and TLĀ ‘if.’ This form with fused IN is more common across sources than simple TLĀ ‘if.’ See IN, TLĀ.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 106.

Horacio Carochi / English: 

intlā = if, when
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), 504.

Lockhart’s Nahuatl as Written: 

combination of subordinator in and optative particle tlā.
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), 220.