Sentence spacing guidance is provided in many language and style guides. The majority of style guides that use a Latin-derived alphabet as a language base now prescribe or recommend the use of a single space after the concluding punctuation of a sentence.;

Background Historical style guides before the 20th century typically indicated that wider spaces were to be used between sentences.University of Chicago Press 1911 The Chicago Manual of Style. p. 101. Standard word spaces were about one-third of an em space, but sentences were to be divided by a full em-space. With the arrival of the typewriter in the late 19th century, style guides for writers began diverging from printer's manuals, indicating that writers should double-space between sentences. This held for most of the 20th century until the computer began replacing the typewriter as the primary means of creating text. In the 1990s, style guides reverted to recommending a single-space between sentences. However, instead of a slightly larger sentence space, style guides simply indicated a standard word space. This is now the convention for publishers.

Style guides are important to writers since "virtually all professional editors work closely with one of them in editing a manuscript for publication".Stevenson 2005. p. viii. Comprehensive style guides, such as the Oxford Style Manual in the United Kingdom and style guides developed by the American Psychological Association, and the Modern Language Association in the United States, provide standards for a wide variety of writing, design, and English language topics—such as grammar, punctuation, and typographic conventions—and are widely used regardless of profession.

Many style guides do not provide guidance on sentence spacing. In some cases, the spacing of the volume or work itself provides an indication of the recommendation for usage of sentence spacing.* A lack of guidance on sentence spacing is also notable for style guides in languages which did not adopt double sentence spacing to accommodate the mechanical limitations of the typewriter, and which conform to the current convention for published work, single sentence spacing.Felici 2003. p. 81; Strizver 2010; ; ; Williams 2003. p. 14. Most language guides for languages with prescriptive guidance provided by an academy also do not provide advice on sentence spacing.

Language guides

Some languages have academies that set language rules. Their publications typically address orthography and grammar as opposed to matters of typography. Style guides are less relevant for these languages since their academies set prescriptive rules.

For example, the Académie française publishes the Dictionnaire de l'Académie française for French speakers worldwide. French is spoken in 57 countries and territories throughout the world, including Europe, North America, and Francophone Africa. Qu'est-ce que la Francophonie? Although the 1992 edition does not provide guidance on sentence spacing, its text is single sentence spaced throughoutconsistent with historical French spacing.

The German language manual Empfehlungen des Rats für deutsche Rechtschreibung, or "Recommendations of the Council for German Orthography" (2006), does not address sentence spacing. However, the manual itself uses one space after terminal punctuation. This is likely because the double-space convention was not prescribed in historical German language guides. Additionally, the Duden, the German-language dictionary most commonly used in Germany, indicates that double sentence spacing is an error. The Duden was the primary orthography and language guide in Germany until the German orthography reform of 1996 created a multinational council for German orthography for German-speaking countriescomposed of experts from Germany, Austria, Liechtenstein and Switzerland. The current version of the Duden reflects the most recent opinions of this council.

The Spanish language is similar. The most important body within the Association of Spanish Language Academies, the Royal Spanish Academy, publishes the Diccionario de la lengua española, which is viewed as prescriptive for the Spanish language worldwide. The 1999 edition does not provide sentence spacing guidance, but is itself single sentence-spaced.

International style guides The European Union's Interinstitutional Style Guide indicates that single sentence spacing is to be used in all European Union publications, encompassing 23 languages. This manual is "obligatory" for all those in the EU who are involved in preparing EU documents and works . It is intended to encompass 23 languages within the European Union .

For the English language, the European Commission's English Style Guide states that sentences are always single-spaced.

The Style manual for authors, editors and printers (6th edn, 2002), sponsored by the Australian Government, stipulates that only one space is used after "sentence-closing punctuation", and that "Programs for word processing and desktop publishing offer more sophisticated, variable spacing, so this practice of double spacing is now avoided because it can create distracting gaps on a page."

National languages not covered by an authoritative language academy typically have multiple style guides—which may not all discuss sentence spacing. This is the case in the United Kingdom. However, the Oxford Style Manual (2003) and the Modern Humanities Research Association's MHRA Style Guide (2002), state that only single spacing should be used.; In Canada, both the English and French language sections of the Canadian Style, A Guide to Writing and Editing (1997), prescribe single sentence spacing.; In the United States, many style guides—such as The Chicago Manual of Style (2003)—allow only single sentence spacing.; ; A comprehensive style guide for general and academic use in Italy, Il Nuovo Manuale di Stile (2009), The style guide itself is single sentence spaced. does not address sentence spacing, but the Guida di Stile Italiano (2010), the official guide for Microsoft translation, tells users to use single sentence spacing "instead of the double spacing used in the United States".

U.S. government style guides Since 1895, the United States Government Publishing Office (GPO) and its predecessors has been authorized by statute to "determine the form and style" of government publications. Quoting (originally chapter 23, § 51, , enacted January 12, 1895). The 1959 edition of the United States Government Printing Office Style Manual prescribed an em space, equivalent to two word spaces, between sentences. The 1967 edition, however, states: "To conform with trade practice, a single justification space (close spacing) will be used between sentences." Subsequent editions of the government's style manual have continued to prescribe a single word space between sentences: "A single justified word space will be used between sentences (key one space when typing). This applies to all types of composition."

General and academic style guides The 2003 edition of the Oxford Style Manual combined the Oxford Guide to Style (first published as Hart's Rules in 1893) and the Oxford Dictionary for Writers and Editors ("defines the language of the entire English-speaking world, from North America to South Africa, from Australia and New Zealand to the Caribbean"). It states, "In text, use only a single word space after all sentence punctuation."

The Chicago Manual of Style is a comprehensive and widely used style manual for American English writing, and has been called the "standard of the book publishing industry". The 16th edition, published in 2010, states, "Like most publishers, Chicago advises leaving a single character space, not two spaces, between sentences ... and this recommendation applies to both the manuscript and the published work."University of Chicago Press, The Chicago Manual of Style 2003. p. 61. Chicago provides further guidance as follows: Punctuation and space—one space or two? In typeset matter, one space, not two should be used between two sentences—whether the first ends in a period, a question mark, an exclamation point, or a closing quotation mark or parenthesis.University of Chicago Press, The Chicago Manual of Style 2010. p. 308.

The Turabian Style, published as the Manual for Writers of Research Papers, Theses, and Dissertations, is widely used in academic writing. The 7th Edition, published in 2007, stipulates that the use of periods, question marks, and exclamation points as "terminal punctuation" to end a sentence should be followed by a single space.

Until the early 2000s, the Modern Language Association (MLA) left room for its adherents to single or double sentence space. In 2008, it modified its position on sentence spacing to the following:

In an earlier era, writers using a typewriter commonly left two spaces after a period, a question mark, or an exclamation point. Publications in the United States today usually have the same spacing after concluding punctuation marks as between words on the same line. Since word processors make available the same fonts used by typesetters for printed works, many writers, influenced by the look of typeset publications, now leave only one space after a concluding punctuation mark. In addition, some publishers' guidelines for preparing a manuscript's electronic files ask professional authors to type only the spaces that are to appear in print. Because it is increasingly common for manuscripts to be prepared with a single space after all concluding punctuation marks, this spacing is recommended and shown in the examples in this manual.Modern Language Association 2008. p. 99.

Scientific style guides

APA style