- Letter (alphabet)
A letter is an element in an
alphabetic system of writing, such as the Greek alphabetand its descendants. Each letter in the written language is usually associated with one phoneme(sound) in the spoken form of the language. Written signs in earlier writings are best called syllabograms (which denote a syllable) or logograms (which denote a word or phrase).
Overview and usage
As symbols that denote segmental speech, letters are associated with
phonetics. In a purely phonemicalphabet, a single phoneme is denoted by a single letter, but in history and practice letters often denote more than one phoneme. A pair of letters designating a single phoneme is called a digraph. Examples of digraphs in English include "ch", "sh" and "th". A phoneme can also be represented by three letters, called a trigraph. An example is the combination "sch" in German.
A letter may also be associated with more than one phoneme, with the phoneme depending on the surrounding letters or etymology of the word. As an example of positional effects, the Spanish letter c is pronounced [k] before "a", "o", or "u" (e.g. "cantar", "corto", "cuidado"), but is pronounced [s] before "e" or "i" (e.g. "centimo", "ciudad").
Letters also have specific names associated with them. These names may differ with language, dialect and history.
Z, for example, is usually called "zed" in all English-speaking countries except the U.S., where it is named "zee".
Letters, as elements of alphabets, have prescribed orders. This may generally be known as "alphabetical order" though
collationis the science devoted to the complex task of ordering and sorting of letters and words in different languages. In Spanish, for instance, ñis a separate letter being sorted after n. In English, n and ñ are sorted alike.
Letters may also have numerical value. This is true of
Roman numeralsand the letters of other writing systems. In English, Arabic numeralsare typically used instead of letters.
The invention of letters was preceded by the West Semitic script, which appeared in Canaan around
1000 BC. Antecedents are suspected in the Proto-Canaanitewriting, dated to around 1800 BC, Virtually all alphabets have their ultimate origins from this system. The Greek alphabetwas invented around 800 BC.
Types of letters
The following "alphabets" (not all are alphabets) and individual letters are discussed in related articles. Each represents a different script:
Arabic alphabet: (Alphabetical from right to left) _ar. ﺍ, _ar. ﺏ, _ar. ﺕ, _ar. ﺙ, _ar. ﺝ, _ar. ﺡ, _ar. ﺥ, _ar. ﺩ, _ar. ﺫ, _ar. ﺭ, _ar. ﺯ, _ar. ﺱ, _ar. ﺵ, _ar. ﺹ, _ar. ﺽ, _ar. ﻁ, _ar. ﻅ, _ar. ﻉ, _ar. ﻍ, _ar. ﻑ, _ar. ﻕ, _ar. ﻙ, _ar. ﻝ, _ar. ﻡ, _ar. ﻥ, _ar. هـ, _ar. ﻭ, _ar. ﻱ. Cyrillic alphabet: А, Б, В, Г, Ґ, Д, Е, Є, Ж, З, И, І, Ї, Й, К, Л, М, Н, О, П, Р, С, Т, У, Ф, Х, Ц, Ч, Ш, Щ, Ю, Я, Ъ, Ь, Ђ, Љ, Њ, Ћ, Џ. Latin alphabet: A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z.
For other writing systems and their letters, see
List of writing systemsand List of alphabets.
Upper and lower case
Some writing systems have two major forms for each letter: an "upper case" form (also called "capital" or "
majuscule") and a " lower case" form (also called "minuscule"). Upper and lower case forms represent the same sound, but serve different functions in writing. Capital letters are most often used at the beginning of a sentence, as the first letter of a proper name, or in inscriptions or headers. They may also serve other functions, such as in the German languagewhere all nouns begin with capital letters.
Typeface and font
A letter may be printed in a number of different sizes or forms, depending on choice of typeface. A
typefaceis a single, stylistically consistent set of forms for letters (or glyphs). A particular typeface may alter standard forms of characters, may present them with different optical weight, or may angle or embellish their forms. A font is more specific than a typeface, since it specifies the size of the letters as well as the form.
Alphabets derived from the Latin
Greek letters used in mathematics
History of the alphabet
Roman letters used in mathematics
* Daniels, Peter T., and William Bright, eds. 1996. The World's Writing Systems. ISBN 0-19-507993-0.
* Powell, Barry B.. 1991. Homer and the Origin of the Greek Alphabet. ISBN-13: 9780521589079 | ISBN-10: 052158907X.
* [http://www.unicode.org/charts/ Unicode Code Charts]
* [http://www.lettercount.com/ LetterCount.com] Count the number of letters in a document
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