Phonological Evolution of Modern Fask from Proto-IndoEuropean

Pre-Proto-Fask

Allophonic colouring of /e/ adjacent to laryngeal consonants:

Merging of PIE "palatovelar" and "velar" plosives ("centumisation"):

Epenthesis of /a/ before syllabic sonorant followed by laryngeal and sonorant:

Loss of laryngeals, phonemicising the allophones of /e/:

Word-initial laryngeals are lost before a consonant — *h₁dóntm̥ 'tooth, acc.' → *dóntum
Laryngeals are lost before vowels — *h₁ésti "is" → *ésti
Laryngeals are lost after vowels but lengthen the preceding vowel: /VH/ > /Vː/ — *séh₁mō "seeds" → *sēmō
Two vowels that come to stand in hiatus because of that change contract into an long vowel — *-oHom "genitive plural" → *-ōm; *-eh₂es "eh₂-stem nom. pl." > *-ās

An epenthetic /s/ was inserted already in PIE after dental consonants when they were followed by a suffix beginning with a dental.

This sequence now becomes /TsT/ > /ts/ > /ss/ — *wid-tós "known" (pronounced *widstos) → *witstós → *wissós

Labiovelars are delabialised before /t/:

Labialisation of velars following /w/:

Merging of PIE aspirated and voiced plosives (deaspiration):

Epenthesis of /i/ after syllabic liquids followed by a plosive:

Epenthesis of /a/ before the remaining syllabic resonants:

Loss of all remaining nonsyllabic laryngeals.

Lenition of /p/ before liquids (pL → bL):

Monophthongisation of /ey/ → /ē/.

Lowering of /uwa/ → /owa/.

Raising of /ō/ → /ā/.

Approximation of /p/ before nasals:

Lowering of /ew/ → /ow/.