quemaca.

Headword: 
quemaca.
Principal English Translation: 

yes; it is true

IPAspelling: 
keːmɑhkɑ
Alonso de Molina: 

quemaca. sí. afirmando algo.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 88v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

QUĒMAHCA yes / si, afirmando algo (M) [(2)Cf.98r,110v]. According to C, this is more polite than QUĒMAH alone.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 208.

Andrés de Olmos: 

Quema, quemaca, si.
Andrés de Olmos, Arte para aprender la lengua Mexicana, ed. Rémi Siméon, facsimile edition ed. Miguel León-Portilla (Guadalajara: Edmundo Aviña Levy, 1972), 185.

Lockhart’s Nahuatl as Written: 

particle. yes. quēn, ah negative, ca (adverbial ending or introductory particle?). 231
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), 231.

Attestations from sources in English: 

Ca quemaca. Yes.
Bartolomé de Alva, A Guide to Confession Large and Small in the Mexican Language, 1634, eds. Barry D. Sell and John Frederick Schwaller, with Lu Ann Homza (Norman: University of Oklahoma Press, 1999), 103.

Attestations from sources in Spanish: 

Ca quemaca. = sí
Bartolomé de Alva, A Guide to Confession Large and Small in the Mexican Language, 1634, eds. Barry D. Sell and John Frederick Schwaller, with Lu Ann Homza (Norman: University of Oklahoma Press, 1999), 102-103.

Ca quemaca = sí (centro de México, 1600)
Fray Juan Bautista, Advertencias para los confesores de los naturales (Primera Parte). Primeros Libros, http://www.primeroslibros.org.

Quemacatzin = sí
Antonio Vázquez Gastelu, Arte de lengua mexicana (Puebla de los Angeles, México: Imprenta Nueva de Diego Fernández de León, 1689), 33v.