Xi (letter) dialects of most of the Greek mainland and Euboea, the sound [ks] was represented by Χ (which in classical Greek is chi, used for ). Because this variant of the Greek alphabet was used in Italy, the Latin alphabet borrowed Χ rather than Ξ as the Latin letter X. While having no Latin derivative, the Xi was adopted into the early Cyrillic alphabet, as the letter ksi (Ѯ, ѯ). The uppercase letter Ξ is used as symbol for: The lowercase letter ξ is used as a symbol for: These characters are used only as mathematical symbols. Stylized Greek text should
History of the Greek alphabet for Semitic languages, and these "matres lectionis", as well as several Phoenician letters which represented consonants not present in Greek, were adapted according to the acrophonic principle to represent Greek vowels consistently, if not unambiguously. The Greek alphabet was developed by a Greek with first-hand experience of contemporary Phoenician script. Almost as quickly as it was established in the Greek mainland, it was rapidly re-exported, eastwards to Phrygia, where a similar script was devised. It was also exported westwards with Euboean or West Greek traders, where the Etruscans adapted the Greek alphabet to their own language, which eventually led to