History of the Greek alphabet consonant letter, rather than seemingly have two exceptions in spelling. Greek, like Phoenician, made a distinction for vowel length; indeed, Greek had five short vowels and seven long vowels, but only five vowel letters. As in Phoenician, the difference in length was not originally made in writing. However, by the 6th century BC the letter eta (not needed for a consonant in eastern dialects of Greek, which lacked ) came to stand for the long vowel , and a new letter, omega, was developed for long . The provenance of omega is not known, but it is generally assumed to
Psi (letter) Psi (letter) Psi (; uppercase ', lowercase '; "psi" ) is the 23rd letter of the Greek alphabet and has a numeric value of 700. In both Classical and Modern Greek, the letter indicates the combination /ps/ (as in English word "lapse"). For Greek loanwords in Latin and modern languages with Latin alphabets, psi is usually transliterated as "ps". The letter's origin is uncertain. It may or may not derive from the Phoenician alphabet. It appears in the 7th century BC, expressing /ps/ in the Eastern alphabets, but /kʰ/ in the Western alphabets (the sound expressed by Χ in the