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
Greek alphabet an additional diacritic in certain words, the so-called iota subscript, which has the shape of a small vertical stroke or a miniature below the letter. This iota represents the former offglide of what were originally long diphthongs, (i.e. ), which became monophthongized during antiquity. Another diacritic used in Greek is the diaeresis (), indicating a hiatus. This system of diacritics was first developed by the scholar Aristophanes of Byzantium ( 257 – 185/180 BC), who worked at the Musaeum in Alexandria during the third century BC. Aristophanes of Byzantium also was the first to divide poems into lines, rather than