Greek alphabet glottal ("heth") was borrowed in two different functions by different dialects of Greek: as a letter for /h/ (Η, heta) by those dialects that had such a sound, and as an additional vowel letter for the long (Η, eta) by those dialects that lacked the consonant. Eventually, a seventh vowel letter for the long (Ω, omega) was introduced. Greek also introduced three new consonant letters for its aspirated plosive sounds and consonant clusters: Φ ("phi") for , Χ ("chi") for and Ψ ("psi") for . In western Greek variants, Χ was instead used for and Ψ for . The origin
History of the alphabet Two variants of the Phoenician alphabet had major impacts on the history of writing: the Aramaic alphabet and the Greek alphabet. The Phoenician and Aramaic alphabets, like their Egyptian prototype, represented only consonants, a system called an "abjad". The Aramaic alphabet, which evolved from the Phoenician in the 7th century BCE, to become the official script of the Persian Empire, appears to be the ancestor of nearly all the modern alphabets of Asia: By at least the 8th century BCE the Greeks borrowed the Phoenician alphabet and adapted it to their own language, creating in the process the first "true"