† Called σίγμα τελικό (sígma
telikó, “final sigma”),
this letter is only used as the final letter of a word. Like the Hebrew
Letters which are no longer used in Modern Greek or have
Greek aintroduced three new consonant letters for its
aspirated plosive sounds and consonant clusters: Φ (phi)
for /pʰ/, Χ (chi) for /kʰ/ and Ψ (psi) for /ps/. In western Greek variants, Χ
was instead used for /ks/ and Ψ for /kʰ/. The origin of these letters
is a matter of some debate.
Three of the original Phoenician letters dropped out of use
before the alphabet took its classical shape:
the letter Ϻ (san), which had
been in competition with Σ (sigma)
denoting the same phoneme /s/;
the letter Ϙ (qoppa),
which was redundant with Κ (kappa)
for /k/, and Ϝ (digamma),
whose sound value /w/ dropped out of the spoken language before or
during the classical period.
Greek was originally written predominantly from right to left,
just like Phoenician,
but scribes could freely alternate between directions.
For a time, a writing style with alternating right-to-left
and left-to-right lines (called boustrophedon,
after the manner of an ox ploughing a field) was common,
until in the classical period the left-to-right writing direction
became the norm.
Individual letter shapes were mirrored depending on the writing
direction of the current line.