This proto-language is reconstructed based on evidence from modern Quechuan languages, as well as records of ancient forms.
Proto-Quechuan was likely spoken in the central region of ancient Peru according to Alfredo Torero.
At the beginning of the fifth century, the proto-Quechua would have crossed the mountain range to settle in the central highlands (Mantaro Valley), then proto-Aymara-speaking, producing the division between Quechua I (to the east) and Quechua II.
The vicinity of a uvular consonant produces more centralized allophones such as [ɑ], [e], [ɛ], [o], [ɔ] and that of the semiconsonant palatal approximant /j/ also causes an overtaking of /a/ to [æ].
The following table shows the numerals in Proto-Quechuan and its evolution in different modern Quechua languages: