(1) Weakened from a diphthong (96-101; 108), or which are the result of
contraction (118): as, #concīdō# from #caedō#; #cōgō# from #co-agō#.
(2) Lengthened by compensation (121): as, #quīnī# for #*quincnī#.
(3) Before #nf#, #ns#, often before #nc# followed by a consonant, and,
in some cases, before #gn# (122).