Proto-Quechuan language
Proto-Quechuan language is the hypothetical mother tongue or proto-language that would have given rise to the various languages of the Quechuan languages. This proto-language is reconstructed based on evidence from modern Quechuan languages, as well as records of ancient forms.

Development
Proto-Quechuan was likely spoken in the central region of ancient Peru according to Alfredo Torero. It then expanded southwards to replace Aymara. At the beginning of the fifth century, the proto-Quechua would have crossed the mountain range to settle in the central highlands (Valle del Mantaro), then  proto-Aymara-speaking, producing the division between  Quechua I  (to the east) and  Quechua II.

Phonology 
The  syllables of the Quechua languages are composed of at least one  vowel as  nucleus. As a general rule, the syllables allow a consonant in position  of onset and coda (beginning and end of syllable, respectively).

Three vowel phonemes are distinguished: a vowel  open   and  closed rounded vowel  unrounded  . The precise pronunciation of these  vowel phonemes varies with their phonetic environment. The vicinity of a uvular consonant produces  more  centralized allophones such as  ,  ,  ,  ,  and that of the  semiconsonant palatal approximant   also causes an overtaking of   to  .  As for the  consonants, Proto-Quechua would have had three  nasal consonant  four  occlusive  , two  affricates  , three  fricatives  , two  approximants   and two or three  liquid  .

Phonetic correspondences 
The following table shows the numerals in Proto-Quechuan and its evolution in different modern Quechua languages:

References 

 
 
 
 
 

Quechuan