From Proto-Trengic to Proto-Treng:
1. V > ∅ / VC_#
2. {m̰ ᵐb} {n̰ ⁿd ᶮɖ͡ʐ} ᵑg > m n ŋ / _#
3. m̰ n̰ > ɓ ɗ
4. b d g > p t k
5. ᵐb ⁿd ᶮɖ͡ʐ ᵑg > p t ʈ k / #_
6. ᵐb ⁿd ᶮɖ͡ʐ ᵑg > mp nt ɳʈ ŋk
7. j w > ɕ ɸ / _#
8. (n)t s > (ɳ)ʈ ʂ / V[-front]_
9. k > kʷ / V[+round](ŋ)_
10. V > ∅ / VN_O[-glottal]V
11. N > N[+POA] / _O[+POA]
12. o u > e i / not breathy
13. {a e} i > ʌ u / breathy
14. V[+breathy] > V[-breathy]
15. h > ∅
16. t s ɾ > t͡ɕ ɕ ʂ / _V[+front]
17. k > t͡ɕ / _V[+front]V
18. V > ∅ / _V
19. p > ɸ / ! m_