In this 2019 revision I have provided pronunciation suggestions for diphthongs and digraphs. A diphthong is a combination of two vowel sounds, gliding from one to the other, as the oy in boy. A digraph is a single sound represented by two letters like the th in think.

Alpha Iota
e as in set, like ε
e as in set, like ε
i as in high

Epsilon Iota
ee /i/ as in meet
ee /i/ as in meet
ai /eɪ/ as in braid

Omicron Iota
ee /i/ as in meet
Similar to German ü, like υ
oi as in boil

Omicron Upsilon
oo as in boot
oo as in boot
oo as in boot

Upsilon Iota
ui as in suite
ui as in suite
ui as in quit or
ui as in suite

Alpha Upsilon
av as in have before voiced consonants
af as in after before unvoiced consonants (π, τ, κ, φ, θ, χ)
av as in have before voiced consonants or any vowel
af as in after before unvoiced consonants (π, τ, κ, φ, θ, χ)
ow as in how

Epsilon Upsilon
ev as in every before voiced consonants or any vowel
ef as in effort before unvoiced consonants (π, τ, κ, φ, θ, χ)
ev as in every before voiced consonants or any vowel
ef as in effort before unvoiced consonants (π, τ, κ, φ, θ, χ)
ε + υ pronounced as a single syllable

Eta Upsilon
ev as in evening before voiced consonants or any vowel, but eef as in beef before unvoiced consonants (π, τ, κ, φ, θ, χ)
av as in behave before voiced consonants or any vowel, but af as in safe before unvoiced consonants (π, τ, κ, φ, θ, χ)
η + υ pronounced as a single syllable

Mu Pi
b as in back,
or sometmes mb
b as in back,
or sometmes mb
μ + π pronounced as a consonant blend maintaining the unvoiced sound of π.

Nu Tau
d as in dog,
or sometimes nd
d as in dog,
or sometimes nd
ν + τ pronounced as a cosonant blend maintianing the unvoiced sound of τ.