Punctuation (or sometimes interpunction) is the use of spacing, conventional signs (called punctuation marks), and certain typographical devices as aids to the understanding and correct reading of written text, whether read silently or aloud. Encyclopædia Britannica: "Punctuation. Another description is, "It is the practice, action, or system of inserting points or other small marks into texts in order to aid interpretation; division of text into sentences, clauses, etc., by means of such marks." Oxford English Dictionary, definition 2a.
In written English, punctuation is vital to disambiguate the meaning of sentences. For example: "woman, without her man, is nothing" (emphasizing the importance of men to women), and "woman: without her, man is nothing" (emphasizing the importance of women to men) have very different meanings; as do "eats shoots and leaves" (which means the subject consumes plant growths) and "eats, shoots, and leaves" (which means the subject eats first, then fires a weapon, and then leaves the scene).Lynne Truss (2003). . Profile Books. . The sharp differences in meaning are produced by the simple differences in punctuation within the example pairs, especially the latter.
The rules of punctuation vary with language, location, register, and time and are constantly evolving. Certain aspects of punctuation are stylistic and are thus the author's (or copy editing) choice, or tachygraphy (shorthand) language forms, such as those used in online chat and Text messaging.
Ancient Chinese classical texts were transmitted without punctuation. However, many Warring States period bamboo texts contain the symbols and indicating the end of a chapter and full stop, respectively.林清源，《簡牘帛書標題格式研究》台北： 藝文印書館，2006。(Lin Qingyuan, Study of Title Formatting in Bamboo and Silk Texts Taipei: Yiwen Publishing, 2006.) . By the Song dynasty, addition of punctuation to texts by scholars to aid comprehension became common.The History of the Song Dynasty (1346) states 「凡所讀書，無不加標點。」 (Among those who read texts, there are none who do not add punctuation).
The earliest writing – Phoenician, Hebrew, and others of the same family – had no capitalization, no spaces, no vowels (see abjad) and few punctuation marks. This worked as long as the subject matter was restricted to a limited range of topics (for example, writing used for recording business transactions). Punctuation is historically an aid to reading aloud.
The oldest known document using punctuation is the Mesha Stele (9th century BC). This employs points between the words and horizontal strokes between the sense section as punctuation.
The Ancient Rome () also occasionally used symbols to indicate pauses, but the Greek théseis—under the name distinctionesThe Latin names for the marks: subdistinctio, media distinctio, and distinctio.—prevailed by the 4th century AD as reported by Aelius Donatus and Isidore of Seville (7th century). Also, texts were sometimes laid out per capitula, where every sentence had its own separate line. Diples were used, but by the late period these often degenerated into comma-shaped marks.
In the 7th–8th centuries Irish people and Anglo-Saxons scribes, whose were not derived from Latin, added more visual cues to render texts more intelligible. Irish scribes introduced the practice of word separation. Likewise, insular scribes adopted the distinctiones system while adapting it for minuscule script (so as to be more prominent) by using not differing height but rather a differing number of marks—aligned horizontally (or sometimes triangularly)—to signify a pause's value: one mark for a minor pause, two for a medium one, and three for a major. Most common were the punctus, a comma-shaped mark, and a 7-shaped mark (comma positura), often used in combination. The same marks could be used in the margin to mark off quotations.
In the late 8th century a different system emerged in Francia under the Carolingian dynasty. Originally indicating how the voice should be modulation when chanting the liturgy, the positurae migrated into any text meant to be read aloud, and then to all manuscripts. Positurae first reached England in the late 10th century, probably during the Benedictine reform movement, but was not adopted until after the Norman conquest. The original positurae were the punctus, punctus elevatus, punctus versus, and punctus interrogativus, but a fifth symbol, the punctus flexus, was added in the 10th century to indicate a pause of a value between the punctus and punctus elevatus. In the late 11th/early 12th century the punctus versus disappeared and was taken over by the simple punctus (now with two distinct values).Raymond Clemens & Timothy Graham, Introduction to Manuscript Studies (Ithaca–London: Cornell UP, 2007), 84–6.
The late Middle Ages saw the addition of the virgula suspensiva (slash or slash with a midpoint dot) which was often used in conjunction with the punctus for different types of pauses. Direct quotations were marked with marginal diples, as in Antiquity, but from at least the 12th century scribes also began entering diples (sometimes double) within the column of text.
The introduction of a standard system of punctuation has also been attributed to the Venetian printers Aldus Manutius and his grandson. They have been credited with popularizing the practice of ending sentences with the colon or full stop (period), inventing the semicolon, making occasional use of parentheses, and creating the modern comma by lowering the virgule. By 1566, Aldus Manutius the Younger was able to state that the main object of punctuation was the clarification of syntax.
By the 19th century, punctuation in the western world had evolved "to classify the marks hierarchically, in terms of weight". Cecil Hartley's poem identifies their relative values:
These simplifications have been carried forward into digital writing, with and the ASCII character set essentially supporting the same characters as typewriters. Treatment of whitespace in HTML discouraged the practice (in English prose) of putting two full spaces after a full stop, since a single or double space would appear the same on the screen. (Some style guides now discourage double spaces, and some electronic writing tools, including Wikipedia's software, automatically collapse double spaces to single.) The full traditional set of typesetting tools became available with the advent of desktop publishing and more sophisticated . Despite the widespread adoption of character sets like Unicode that support the punctuation of traditional typesetting, writing forms like text messages tend to use the simplified ASCII style of punctuation, with the addition of new non-text characters like emoji. Informal text speak tends to drop punctuation when not needed, including some ways that would be considered errors in more formal writing.
In the computer era, punctuation characters were recycled for use in programming languages and . Due to its use in email and Twitter handles, the at sign (@) has gone from an obscure character mostly used by sellers of bulk commodities (10 pounds @$2.00 per pound), to a very common character in common use for both technical routing and an abbreviation for "at". The tilde (~), in moveable type only used in combination with vowels, for mechanical reasons ended up as a separate key on mechanical typewriters, and like @ it has been put to completely new uses.
In Greek language, the question mark is written as the English semicolon, while the functions of the colon and semicolon are performed by a raised point , known as the ano teleia (άνω τελεία).
In Georgian, three dots, , were formerly used as a sentence or paragraph divider. It is still sometimes used in calligraphy.
Spanish language and Asturian (both of them Romance languages used in Spain) use an inverted question mark at the beginning of a question and the normal question mark at the end, as well as an inverted exclamation mark at the beginning of an exclamation and the normal exclamation mark at the end.
Armenian uses several punctuation marks of its own. The full stop is represented by a colon, and vice versa; the exclamation mark is represented by a diagonal similar to a tilde , while the question mark resembles an unclosed circle placed after the last vowel of the word.
Arabic, Urdu, and Persian language—written from right to left—use a reversed question mark: , and a reversed comma: . This is a modern innovation; pre-modern Arabic did not use punctuation. Hebrew language, which is also written from right to left, uses the same characters as in English, and .
Originally, Sanskrit had no punctuation. In the 17th century, Sanskrit and Marathi language, both written using Devanagari, started using the vertical bar to end a line of prose and double vertical bars in verse.
Punctuation was not used in Chinese language, Japanese, and Korean language writing until the adoption of punctuation from the West in the late 19th and early 20th century. In unpunctuated texts, the grammatical structure of sentences in classical writing is inferred from context.
In the Indian subcontinent, is sometimes used in place of colon or after a subheading. Its origin is unclear, but could be a remnant of the British Raj. Another punctuation common in the Indian Subcontinent for writing monetary amounts is the use of or after the number. For example, Rs. 20/- or Rs. 20/= implies 20 rupees whole.
Thai language, Khmer language, Lao language and Burmese language did not use punctuation until the adoption of punctuation from the West in the 20th century. Blank spaces are more frequent than full stops or commas.