am-.

Headword: 
am-.
Principal English Translation: 

you (plural) (subject prefix); and your (plural possessive, shortened form of amo-, which appears before certain vowels)
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), 1.

Lockhart’s Nahuatl as Written: 

am-. = you (pl.), 2nd person pl. subject prefix; also your (pl.), form of amo-. 2nd person pl. possessive prefix, before certain vowels
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), 210.

Attestations from sources in English: 

in antenanoan, in amjlamatlaca in antzonjztaque (or: in antenanhuan, in amilamatlaca, in antzoniztaque) = ye who are mothers, ye who are old women, ye who are the white-haired ones (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), chapter 35, 195.

in amjlamaiotzin, in amonaiotzin (or in amilamayotzin, in amonayotzin) = your old-womanliness, your motherliness (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), chapter 35, 195.