A letter is a segmental symbol of a phonemic writing system. The inventory of all letters forms an alphabet. Letters broadly correspond to phonemes in the spoken form of the language, although there is rarely a consistent and exact correspondence between letters and phonemes.
The word letter, borrowed from Old French letre, entered Middle English around 1200 AD, eventually displacing the Old English term bōcstæf (bookstaff). Letter is descended from the Latin littera, which may have descended from the Greek "διφθέρα" (diphthera, writing tablet), via Etruscan.
A letter is a type of grapheme, which is a functional unit in a writing system: a letter (or group of letters) represents visually a phoneme (a unit of sound that can distinguish one word from another in a particular language). Letters are combined to form written words, just as phonemes are combined to form spoken words. A sequence of graphemes representing a phoneme is called a multigraph. A digraph is a case of polygraphs consisting of two graphemes. Examples of digraphs in English include ch, sh, and th. Some phonemes are represented by three letters, called a trigraph, such as sch in German.
The same letterform may be used in different alphabets but have different sounds. The letters ⟨H⟩, ⟨Η⟩ and ⟨Н⟩ look rather alike but are the Latin H, Greek eta and Cyrillic en respectively; conversely the letters ⟨S⟩, ⟨Σ⟩ (sigma) and ⟨С⟩ (Es (Cyrillic)) from these alphabets each represent (approximately) the same [s] sound. The basic Latin alphabet is used by hundreds of languages around the world, but there are many other alphabets.
Specific names are associated with letters, which may differ with language, dialect, and history. Z, for example, is usually called zed in all English-speaking countries except the US, where it is named zee. As elements of alphabets, letters have prescribed orders, although this too may vary by language. In Spanish, for instance, ⟨ñ⟩ is a separate letter, sorted separately from ⟨n⟩: this distinction is not usually recognised in English dictionaries. (In computer systems, each has its own unique code point, U+006E n N and U+00F1 ñ LATIN SMALL LETTER N WITH TILDE, respectively.)
Letters may also have a numerical or quantitative value. This applies to Roman numerals and the letters of other writing systems. In English, Arabic numerals are typically used instead of letters. Greek and Latin letters have a variety of modern uses in mathematics, science, and engineering.
People and objects are sometimes named after letters, for one of these reasons:
Before there were alphabets there were pictographs: small pictures representing objects and concepts. Ancient Egyptian examples date to about 3000 BCE. citation needed][
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. The Latin alphabet (used in Western and Central Europe and the former European colonies) derives from this Phoenician alphabet, which had 22 letters. Nineteen of the present letters of the Latin alphabet evolved from the early Phoenician forms; letter shapes and order of appearance correspond closely. The Greek alphabet, adapted around 800 BCE, added four letters to the Phoenician list. This Greek alphabet was the first to assign letters not only to consonant sounds, but also to vowels. The Roman Empire brought the development and refinement of the Latin alphabet, beginning around 500 BCE. The Romans added or dropped certain letters to accommodate Greek and Etruscan words; they also experimented with styles such as cursive when writing in ink. By about the fifth century CE, the beginnings of lowercase letterforms began to emerge in Roman writing, but they did not come into common use until the end of the Middle Ages, a thousand years later.
Main article: Letter case
A letter can have multiple variants, or allographs, related to variation in style of handwriting or printing. Some writing systems have two major types of allographs for each letter: an uppercase form (also called capital or majuscule) and a lowercase form (also called minuscule). Upper- and lowercase letters 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 title, or in headers or inscriptions. They may also serve other functions, such as in the German language where all nouns begin with capital letters.
The terms uppercase and lowercase originated in the days of handset type for printing presses. Individual letter blocks were kept in specific compartments of drawers in a type case. Capital letters were stored in a higher drawer or upper case.
Main article: Diacritics
In most alphabetic scripts, diacritics (or accents) are a routinely used. English is unusual in not using them except for loanwords from other languages or personal names (for example, naïve, Brontë). The ubiquity of this usage is indicated by the existence of precomposed characters for use with computer systems (for example ⟨á⟩, ⟨à⟩, ⟨ä⟩, ⟨â⟩, ⟨ã⟩.)
See also: List of writing systems
In the following table, letters from multiple different writing systems are shown, to demonstrate the variety of letters used throughout the world.
|Example alphabet||Letters in example alphabet|
|Assamese alphabet||অ, আ, ই, ঈ, উ, ঊ, ঋ, এ, ঐ, ও, ঔ, ক, খ, গ, ঘ, ঙ, চ, ছ, জ, ঝ, ঞ, ট, ঠ, ড, ঢ, ণ, ত, থ, দ, ধ, ন, প, ফ, ব, ভ, ম, য, ৰ, ল, ৱ, শ, ষ, স, হ,ক্ষ, ড়, ঢ়, য়, ৎ, ং, ঃ, ঁ|
|Bengali alphabet||অ, আ, ই, ঈ, উ, ঊ, ঋ, এ, ঐ, ও, ঔ, ক, খ, গ, ঘ, ঙ, চ, ছ, জ, ঝ, ঞ, ট, ঠ, ড, ঢ, ণ, ত, থ, দ, ধ, ন, প, ফ, ব, ভ, ম, য, ল, শ, ষ, স, হ,ক্ষ, ড়, ঢ়, য়, ৎ, ং, ঃ, ঁ|
|Arabic alphabet||(Alphabetical from right to left) ﺍ, ﺏ, ﺕ, ﺙ, ﺝ, ﺡ, ﺥ, ﺩ, ﺫ, ﺭ, ﺯ, ﺱ, ﺵ, ﺹ, ﺽ, ﻁ, ﻅ, ﻉ, ﻍ, ﻑ, ﻕ, ﻙ, ﻝ, ﻡ, ﻥ, هـ, ﻭ, ﻱ|
|Armenian alphabet||Ա, Բ, Գ, Դ, Ե, Զ, Է, Ը, Թ, Ժ, Ի, Լ, Խ, Ծ, Կ, Հ, Ձ, Ղ, Ճ, Մ, Յ, Ն, Շ, Ո, Չ, Պ, Ջ, Ռ, Ս, Վ, Տ, Ր, Ց, Ւ, Փ, Ք, Օ, Ֆ|
|Syriac alphabet||(Alphabetical from right to left) ܐ, ܒ, ܓ, ܕ, ܗ, ܘ, ܙ, ܚ, ܛ, ܝ, ܟܟ, ܠ, ܡܡ, ܢܢ, ܣ, ܥ, ܦ, ܨ, ܩ, ܪ, ܫ, ܬ|
|Cyrillic script||А, Б, В, Г, Д, Е, Ё, Ж, З, И, Й, К, Л, М, Н, О, П, Р, С, Т, У, Ф, Х, Ц, Ч, Ш, Щ, Ъ, Ы, Ь, Э, Ю, Я|
|Georgian script||ა, ბ, გ, დ, ე, ვ, ზ, თ, ი, კ, ლ, მ, ნ, ო, პ, ჟ, რ, ს, ტ, უ, ფ, ქ, ღ, ყ, შ, ჩ, ც, ძ, წ, ჭ, ხ, ჯ, ჰ|
|Greek alphabet||Α, Β, Γ, Δ, Ε, Ζ, Η, Θ, Ι, Κ, Λ, Μ, Ν, Ξ, Ο, Π, Ρ, Σ, Τ, Υ, Φ, Χ, Ψ, Ω|
|Hebrew alphabet||(Alphabetical from right to left) א, ב, ג, ד, ה, ו, ז, ח, ט, י, כ, ל, מ, נ, ס, ע, פ, צ, ק, ר, ש, ת|
|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|
|Hangul||ㄱ ㄲ ㄴ ㄷ ㄸ ㄹ ㅁ ㅂ ㅃ ㅅ ㅆ ㅇ ㅈ ㅉ ㅊ ㅋ ㅌ ㅍ ㅎ ㅏ ㅐ ㅑ ㅒ ㅓ ㅔ ㅕ ㅖ ㅗ ㅘ ㅙ ㅚ ㅛ ㅜ ㅝ ㅞ ㅟ ㅠ ㅡ ㅢ ㅣ|
|Burmese||က ခ ဂ ဃ င စ ဆ ဇ ဈ ည ဋ ဌ ဍ ဎ ဏ တ ထ ဒ ဓ န ပ ဖ ဗ ဘ မ ယ ရ လ ဝ သ ဟ ဠ အ|
|Bopomofo||ㄅ ㄆ ㄇ ㄈ ㄉ ㄊ ㄋ ㄌ ㄍ ㄎ ㄏ ㄐ ㄑ ㄒ ㄓ ㄔ ㄕ ㄖ ㄗ ㄘ ㄙ ㄚ ㄛ ㄜ ㄝ ㄞ ㄟ ㄠ ㄡ ㄢ ㄣ ㄤ ㄥ ㄦ ㄧ ㄨ ㄩ ㄭ|
|Ogham||ᚁ ᚂ ᚃ ᚄ ᚅ ᚆ ᚇ ᚈ ᚉ ᚊ ᚋ ᚌ ᚍ ᚎ ᚏ ᚐ ᚑ ᚒ ᚓ ᚔ ᚕ ᚖ ᚗ ᚘ ᚙ ᚚ ᚛ ᚜|
|Ethiopic||ሀ ለ ሐ መ ሠ ረ ሰ ሸ ቀ በ ተ ቸ ኀ ነ ኘ አ ከ ኸ ወ ዐ ዘ ዠ የ ደ ጀ ገ ጠ ጨ ጰ ጸ ፀ ፈ ፐ|
|Tifinagh (Amazigh alphabet)||ⴰ, ⴱ, ⵛ, ⴷ, ⴹ, ⴻ, ⴼ, ⴳ, ⴳⵯ, ⵀ, ⵃ, ⵉ, ⵊ, ⴽ, ⴽⵯ, ⵍ, ⵎ, ⵏ, ⵓ, ⵄ, ⵖ, ⵅ, ⵇ, ⵔ, ⵕ, ⵙ, ⵚ, ⵜ, ⵟ, ⵡ, ⵢ, ⵣ, ⵥ|
|Meetei Mayek||ꯀ, ꯁ, ꯂ, ꯃ, ꯄ, ꯅ, ꯆ, ꯈ, ꯉ, ꯊ, ꯋ, ꯌ, ꯍ, ꯎ, ꯏ, ꯐ, ꯑ, ꯒ, ꯓ, ꯔ, ꯕ, ꯖ, ꯗ, ꯘ, ꯙ, ꯚ, ꯛ, ꯜ, ꯝ, ꯞ, ꯟ, ꯠ, ꯡ, ꯢ, ꯥ, ꯤ, ꯨ, ꯦ, ꯣ, ꯩ, ꯧ, ꯪ|