Shin (letter) languages, as follows: In the Arabic alphabet, ' is at the original (21st) position in Abjadi order. A letter variant ' takes the place of Samekh at 15th position. "" represents , and is the 13th letter of the modern alphabet order and is written thus: The Arabic letter "šīn" was an acronym for "something" ( "šayʾ(un)" ) meaning the unknown in algebraic equations. In the transcription into Spanish, the Greek letter "chi" (χ) was used which was later transcribed into Latin "x". According to some sources, this is the origin of "x" used for the unknown in the equations.
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