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 the early western Greek dialects, where the letter eta remained an , gave rise to the Old Italic alphabet which in turn developed into the Old Roman alphabet. In the eastern Greek dialects, which did not have an /h/, eta stood for a vowel, and remains a vowel in modern Greek and all other alphabets derived from the eastern variants: Glagolitic, Cyrillic, Armenian, Gothic (which used both Greek and Roman letters), and perhaps Georgian. Although this description presents the evolution of scripts in a linear fashion, this is a simplification. For example, the Manchu alphabet, descended from the abjads of