Greek alphabet from which the later standard Greek alphabet emerged. Athens used a local form of the "light blue" alphabet type until the end of the fifth century BC, which lacked the letters Ξ and Ψ as well as the vowel symbols Η and Ω. In the Old Attic alphabet, stood for and for . was used for all three sounds (correspondinɡ to classical respectively), and was used for all of (corresponding to classical respectively). The letter (heta) was used for the consonant . Some variant local letter forms were also characteristic of Athenian writing, some of which were shared with the
Letter (alphabet) text than serif faces. Without serifs, an uppercase "I" () is indistinguishable from a lowercase "l" (). The average distribution of letters, or the relative frequency of each letter's occurrence in text in a given language, can be obtained by analyzing large amounts of representative text. This information can be useful in cryptography and for other purposes, such as song lyrics. Letter frequencies vary in different types of writing. Letter (alphabet) A letter is a grapheme (written character) in an alphabetic system of writing. It is a visual representation of the smallest unit of spoken sound. Letters broadly correspond to