SHAPE: Most
cities of both
greek alphabet groups used the
I shape, few ones a crooked line.
SOUND: In ancient greek, it was a
dichronic (two-valued) vowel. Could be either short or long /i/. Later it is always pronounced short, normal [i]. Iota had a very busy life both as a letter symbol and a sound. The
/i/ sound was very important at the '
iotacistic' tendency of pronunciation that prevailed after the first pre-christian centuries: it swallowed up, so to speak, all sorts of old vowel-utterances:
H [ε:]
Y [y]
EI [
ei]
YI [
yi]
OI [
oi]
(but their historical spelling remains the same till today) and
HI [ε:i]. The
iotacistic pronunciation is the counterpart of the '
etacistic' or
Erasmic, that tends to preserve the analytical utterance of vowel combinations.
In modern greek, Iota is uttered as
[j] in some <ια, ιε , ιo, ιoυ> cases: [ja,je,jo,ju]
or sometimes as fast diphthong [ ia,ie,io,iu]. (
phaenomenon of synizesis explained). Hence its name [`jota] instead of [
i`ota] or [i`ota].
NAME: ETYMOLOGY: from northsemitic (phoenician): jōdh = (the) hand. This letter had a semiphonic function (as /i/ and /j/) which survived in greek.
NAME: SPELLING: The
hellenistic greek spelling used
psile for the iota and
perismpomene for the omega:
τα
COMBINATIONS: The letter 'I' was very busy:
DIGRAMMES: AI (with short A), EI, OI, YI used to be pronounced as
diphthongs (as in
erasmic) but later ended up as
monophthongs.
For the so-called 'long diphthongs'
AI αι HI ηι and
ΩI ωι, the mediaeval manuscripts prefer a different form:
adscribe the
I after a capital letter: (ιώτα πρoσγεγραμμένoν)
iota prosgegrammenon =nearbywritten) Hι
subscribe it under a small letter: (ιώτα υπoγεγραμμένoν)
(iota hypogegrammenon=underwritten) 
Look how many occurrences of the hypogegrammene there are in
polytonic script!
MORE GREEK WORDS STARTING WITH IOTA
•ίδιo=same/itself - idio(syncracy), ιδίωμα-idiom
•ίσo=equal - isotope
•ισθμός=isthmus
Iota with daseia < breathing mark: •ιστoρία=history
•ίππoς (ancient greek)=horse, (modern greek=άλoγo) - ιππόδρoμoς=hippodrome
υt