The intonations of declaration are classified in three types, symbolized by the comma (,), used to separate words or phrases for clarity; the semicolon (;), used to mark separation between elements in a series of related phrases, generally in a long sentence; and the full stop, or period (.), used to mark the end of a sentence. Other intonations are shown by the exclamation point (!); the interrogation point, or question mark (?); the parenthesis [( )], used to set off a word or phrase from a sentence that is complete without it; and the colon (:), typically used to introduce material that elaborates on what has already been said. Quotation marks (" ") indicate direct quotation or some borrowing, and usually demand special intonation. The ellipsis (…) is used to indicate the place in a passage where material has been omitted or a thought has trailed off. The long dash (—) is especially used in handwriting for incomplete intonation patterns.
Punctuation of material intended to be read silently rather than aloud—the far more usual case today—has introduced refinements designed to help the reader: brackets ([ ]), a secondary parenthesis; capital letters; paragraphing; and indentation. Two other frequent signs are the apostrophe ('), marking an omission of one or two letters, or a possessive case, and the hyphen (-), marking a line division or an intimate joining, as in compound words. These last two are practically extra letters, and their use, belonging with spelling rather than with punctuation, is highly arbitrary.
Each written language has its tradition of punctuation, often very different from that used in English; thus, in German nouns are capitalized, and in Spanish the beginnings of exclamations and of questions are marked with inverted signs. See also accent.
See W. D. Drake, The Way to Punctuate (1971); Words into Type (3d ed. 1974); D. Hacker, A Writer's Reference (4th ed. 1999); Univ. of Chicago Press, The Chicago Manual of Style (15th ed. 2003).
Punctuation marks are symbols that correspond to neither phonemes (sounds) of a language nor to lexemes (words and phrases), but which serve to indicate the structure and organization of writing, as well as intonation and pauses to be observed when reading it aloud. See orthography.
In English, punctuation is vital to disambiguate the meaning of sentences. For example, "woman, without her man, is nothing," and "woman: without her, man is nothing," have greatly different meanings, as do "eats shoots and leaves" and "eats, shoots and leaves."
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 editor's) choice. Tachygraphic language forms, such as those used in online chat and text messages, may have wildly different rules.
The oldest known document that uses punctuation is the Mesha Stele (9th century BC). This employs points between the words and horizontal strokes between the sense section as punctuation.
The Greeks were using punctuation marks consisting of vertically arranged dots - usually two (c.f. the modern colon) or three - in around the 5th century BC. Greek playwrights (e.g., Euripides and Aristophanes) used symbols to distinguish the ends of phrases in written drama: this essentially helped the play's cast to know when to pause. In particular, they used three different symbols to divide speeches, known as commas (indicated by a centred dot), colons (indicated by a dot on the base line), and periods (indicated by a raised dot).
The Romans (circa 1st century BC) also adopted symbols to indicate pauses.
Punctuation developed dramatically when large numbers of copies of the Christian Bible started to be produced. These were designed to be read aloud and the copyists began to introduce a range of marks to aid the reader, including indentation, various punctuation marks and an early version of initial capitals. St Jerome and his colleagues, who produced the Vulgate translation of the Bible into Latin, developed an early system (circa 400 AD); this was considerably improved on by Alcuin. The marks included the virgule (forward slash) and dots in different locations; the dots were centred in the line, raised or in groups.
The use of punctuation was not standardized until after the invention of printing. Credit for introducing a standard system is generally given to Aldus Manutius and his grandson. They popularized the practice of ending sentences with the colon or full stop, invented the semicolon, made occasional use of parentheses and created the modern comma by lowering the virgule.
The standards and limitations of evolving technologies have exercised further pragmatic influences. For example, minimisation of punctuation in typewritten matter became economically desirable in the 1960s and 1970s for the many users of carbon-film ribbons, since a period or comma consumed the same length of expensive non-reusable ribbon as did a capital letter.
Arabic—written from right to left—uses a reversed question mark: ؟. However, Hebrew, which is also written from right to left, uses the same character as in English (?).
Originally Sanskrit had no punctuation. In the 1600s, Sanskrit and Marathi, both written in the Devanagari script, started using the vertical bar (|) to end a line of prose and double vertical bars (||) in verse.
Although texts in the Chinese, Japanese and Korean languages were often left unpunctuated until the modern era, there has been evidence of punctuation usage in ancient China since at least the Warring States era in the 3rd century BCE. See the Chinese Wikipedia page on punctuation for more information. In unpunctuated texts, the grammatical structure of sentences in classical writing is inferred from context. Most punctuation marks in modern Chinese, Japanese and Korean have similar functions to their English counterparts; however, they often look different and have different customary rules.
Famous Russian designer Artemy Lebedev suggested a double-comma sign, which he believes would communicate a pause better than the semicolon does. Lebedev, however, seems unaware of the widespread use of semicolon in English (in Russian, independent clauses can be separated by commas; as a result, the semicolon is used — infrequently — only for stylistic purposes).