From Ancient Pencil Language to Middle Pencil Language:
Loss of aspiration distinction
p_j > p_C > S (where C is the voiceless palatal fricative)
G > j /_i
Limited word-final devoicing
a > E in stressed syllables
A and a merge together
(vowels) > ∅ /(consonant)_(approximant) in unstressed syllables
ks > sk (random)