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
Letter (alphabet) from cultures that use logograms–word symbols–to represent words take years longer to learn to read and write than children learning an alphabet. The relative ease of memorizing twenty-six letters contributed to the spread of literacy throughout the world. The first consonantal alphabet found emerged around 1800 BCE to represent the language of the Phoenicians, Semitic workers in Egypt (see Middle Bronze Age alphabets), and was derived from the alphabetic principles of the Egyptian hieroglyphs. Our present Roman system derives from this Phoenician alphabet, which had twenty-two letters. Nineteen of our present letters evolved from the early Phoenician forms; letter shapes