I verbi contratti possono essere in -αω, -εω e -οω.
In questi verbi la vocale finale del tema (α, ε, ο) trovandosi in contatto con la vocale tematica ε/ο dà origine alle seguenti contrazioni vocaliche.
α + ο > ω
α + ω > ω
α + ου ω
α + οι > ῳ
α + ε > ᾱ
α + η > ᾱ
α + ει > ᾳ
α + ῃ > ᾳ
ε + ε > ει
ε + ο > ου
ε + η > η
ε + ῃ > ῃ
ε + ω > ω
ε + ει > ει
ε + οι > οι
ε + ου > ου
ο + ο > ου
ο + ε > ου
ο + ου > ου
ο + η > ω
ο + ω > ω
ο + οι > οι
ο + ῃ > οι
ο + ει > οι