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 As in Phoenician, the difference in length was not originally made in writing.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
History of the alphabet All of the names of the letters of the Phoenician alphabet started with consonants, and these consonants were what the letters represented, something called the acrophonic principle. However, several Phoenician consonants were absent in Greek, and thus several letter names came to be pronounced with initial vowels. Since the start of the name of a letter was expected to be the sound of the letter (the acrophonic principle), in Greek these letters came to be used for vowels. For example, the Greeks had no glottal stop or voiced pharyngeal sounds, so the Phoenician letters "’alep" and "`ayin" became Greek "alpha"