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
Delta (letter) represents a voiced dental fricative , like the "th" in "that" or "this". It is romanized as "d" or "dh". The uppercase letter Δ can be used to denote: The lowercase letter δ (or 𝛿) can be used to denote: These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style. Delta (letter) Delta (uppercase Δ, lowercase δ or 𝛿; "délta", ) is the fourth letter of the Greek alphabet. In the system of Greek numerals it has a value of 4. It was