Space (punctuation) explained

Space
See Also:	Other types of spaces

In writing, a space is a blank area that separates words, sentences, syllables (in syllabification) and other written or printed glyphs (characters). Conventions for spacing vary among languages, and in some languages the spacing rules are complex. Inter-word spaces ease the reader's task of identifying words, and avoid outright ambiguities such as "now here" vs. "nowhere". They also provide convenient guides for where a human or program may start new lines.

Typesetting can use spaces of varying widths, just as it can use graphic characters of varying widths. Unlike graphic characters, typeset spaces are commonly stretched in order to align text. The typewriter, on the other hand, typically has only one width for all characters, including spaces. Following widespread acceptance of the typewriter, some typewriter conventions influenced typography and the design of printed works.

Computer representation of text facilitates getting around mechanical and physical limitations such as character widths in at least two ways:

• Character encodings such as Unicode provide spaces of several widths, which are encoded using distinct numeric code points. For example, Unicode U+0020 is the "normal" space character, but U+00A0 adds the meaning that a new line should not be started there, while U+2003 represents a space with a fixed width of one em. Collectively, such characters are called Whitespace characters.
• Formatting and drawing languages and software commonly provide much more flexibility in spacing. For example, SVG, PostScript, and countless other languages enable drawing characters at specific (x,y) coordinates on a screen or page. By drawing each word at a specific starting coordinate, such programs need not "draw" spaces at all (this can lead to difficulties in extracting the correct text back out). Similarly, word processors can "fully justify" text, stretching inter-word spaces to make all lines the same length (as can mechanical Linotype machines). Precision is limited by physical capabilities of output devices.

Use in natural languages

Between words

See main article: article and Word divider.

Modern English uses a space to separate words, but not all languages follow this practice. Spaces were not used to separate words in Latin until roughly 600–800 AD. Ancient Hebrew and Arabic did use spaces partly to compensate in clarity for the lack of vowels.^[1] The earliest Greek script also used interpuncts to divide words rather than spacing, although this practice was soon displaced by the .

Word spacing was later used by Irish and Anglo-Saxon scribes, beginning after the creation of the Carolingian minuscule by Alcuin of York and the scribes' adoption of it. Spacing would become standard in Renaissance Italy and France, and then Byzantium by the end of the 16th century; then entering into the Slavic languages in Cyrillic in the 17th century, and only in modern times entering modern Sanskrit.^[2]

CJK languages do not use spaces when dealing with text containing mostly Chinese characters and kana. In Japanese, spaces may occasionally be used to separate people's family names from given names, to denote omitted particles (especially the topic particle wa), and for certain literary or artistic effects. Modern Korean, however, has spaces as an essential part of its writing system (because of Western influence), given the phonetic nature of the hangul script that requires word dividers to avoid ambiguity, as opposed to Chinese characters which are mostly very distinguishable from each other. In Korean, spaces are used to separate chunks of nouns, nouns and particles, adjectives, and verbs; for certain compounds or phrases, spaces may be used or not, for example the phrase for "Republic of Korea" is usually spelled without spaces as Korean: 대한민국 rather than with a space as Korean: 대한 민국.

Runic texts use either an interpunct-like or a colon-like punctuation mark to separate words. There are two Unicode characters dedicated for this: and .

Between sentences

See main article: article and Sentence spacing.

Languages with a Latin-derived alphabet have used various methods of sentence spacing since the advent of movable type in the 15th century.

• One space (some times called French spacing, q.v.). This is a common convention in most countries that use the ISO basic Latin alphabet for published and final written work, as well as digital (World Wide Web) media.^[3] Web browsers usually do not differentiate between single and multiple spaces in source code when displaying text, unless the text is given a "white-space" CSS attribute. Without this being set, collapsing strings of spaces to a single space allow HTML source code to be spaced in a more machine-readable way, at the expense of control over the spacing of the rendered page.^[4]
• Double space (English spacing). It is sometimes claimed that this convention stems from the use of the monospaced font on typewriters.^[5] However, instructions to use more spacing between sentences than words date back centuries, and two spaces on a typewriter was the closest approximation to typesetters' previous rules aimed at improving readability.^[6] Wider spacing continued to be used by both typesetters and typists until the Second World War, after which typesetters gradually transitioned to word spacing between sentences in published print, while typists continued the practice of using two spaces.^{[7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17]}
• One widened space, typically one-and-a-third to slightly less than twice as wide as a word space. This spacing was sometimes used in typesetting before the 19th century. It has also been used in other non-typewriter typesetting systems such as the Linotype machine^[18] and the TeX system. Modern computer-based digital fonts can adjust the spacing after terminal punctuation as well, creating a space slightly wider than a standard word space.^[19]

There has been some controversy regarding the proper amount of sentence spacing in typeset material. The Elements of Typographic Style states that only a single word space is required for sentence spacing.^[20] Psychological studies suggest "readers benefit from having two spaces after periods."^[21]

Unit symbols and numbers

The International System of Units (SI) prescribes inserting a space between a number and a unit of measurement (the space being regarded as an implied multiplication sign) but never between a prefix and a base unit; a space (or a multiplication dot) should also be used between units in compound units.^[22]

5.0 cm, not or or

45 kg, not or or

, not or

20 kN m or 20 kN⋅m, not or

π/2 rad, not or

50 %, not or (Note: % is not an SI unit, and many style guides do not follow this recommendation; note that is used as adjective, e.g. to express concentration as in 50% acetic acid.)

The only exception to this rule is the traditional symbolic notation of angles: degree (e.g., 30°), minute of arc (e.g., 22′), and second of arc (e.g., 8″).

The SI also prescribes the use of a space^[23] (often typographically a thin space) as a thousands separator where required. Both the point and the comma are reserved as decimal markers.

1 000 000 000 000 (thin space) or 1000000 not 1,000,000 or 1.000.000

1 000 000 000 000 (regular space which is significantly wider)

Sometimes a narrow non-breaking space or non-breaking space, respectively, is recommended (as in, for example, IEEE Standards^[24] and IEC standards^[25]) to avoid the separation of units and values or parts of compounds units, due to automatic line wrap and word wrap.

Encoding

Unicode defines many variants of a single whitespace character, with various properties; the more commonly encountered variations include:

In URLs, spaces are percent encoded with its ASCII/UTF-8 representation %20.

Types of spaces

• Figure space
• Non-breaking space
• Thin space
• Visible space
  • Zero-width space

See also

• Em (typography)
• En (typography)
• Halfwidth and fullwidth forms
• Internal field separator
• Sentence spacing in digital media
• Underscore
• Whitespace character

Further reading

• Book: Saenger, Paul . Space Between Words: The Origin of Silent Reading . Stanford, Calif . Stanford University Press . 1997 . 9780804726535 . 35548786.

Notes and References

1. https://books.google.com/books?id=w3vZaFoaa3EC&pg=PA10 Saenger 2000, p. 10
2. Saenger, Paul. Space Between Words: The Origins of Silent Reading. Stanford University Press, 1997, 9–14.
3. Book: Einsohn , Amy . The Copyeditor's Handbook: A Guide for Book Publishing and Corporate Communications . 2nd . 2006 . University of California Press . Berkeley, Los Angeles, London . 9780520246881 . 113 . Punctuation, Eyeballing every mark . https://books.google.com/books?id=fnhkJ_CjTQIC&pg=PA113 . If you are working on documents that will be printed without any intervention from a compositor (e.g., documents produced on the office laser printer), you will have to carefully scrutinize every piece of punctuation to be sure that the document contains the correct character (see table 5). You should also delete any extra wordspacing before and after punctuation marks. The conventions are: One space follows sentence-ending punctuation mark (period, question mark, or exclamation point). One space follows comma, colon, or semicolon ... . 2010-04-25 .
4. Web site: How many spaces at the end of a sentence? One or two?. Thomas A. Fine. 2013-08-08. 2014-02-20. https://web.archive.org/web/20140220233010/http://www.tomsarazac.com/tom/opinions/space-after-periods.html. live.
5. Space Invaders: Why you should never, ever use two spaces after a period.. Farhad Manjoo. 2011-01-13. Slate. 2011-03-29.
6. Web site: Why two spaces after a period isn't wrong. Heraclitus. 1 November 2011. 8 August 2013. 26 July 2013. https://web.archive.org/web/20130726225645/http://www.heracliteanriver.com/?p=324. live.
7. Book: Felici , James . The Complete Manual of Typography: A Guide to Setting Perfect Type . 2003 . Peachpit Press . Berkeley, CA . 0321127307 . 80 .
8. Web site: The Curious Misconception Surrounding Sentence Spacing. David Spencer. 24 May 2011. Type Desk. Matador. 27 May 2011. 10 June 2011. https://web.archive.org/web/20110610152438/http://typedesk.com/2011/05/24/the-curious-misconception-surrounding-sentence-spacing/. live.
9. Book: Bringhurst , Robert . The Elements of Typographic Style . 3 . 2004 . Hartley & Marks . Washington and Vancouver . 0881792063 . 28 . 2.1.4 Use a single word space between sentences. In the nineteenth century, which was a dark and inflationary age in typography and type design, many compositors were encouraged to stuff extra space between sentences. Generations of twentieth century typists were then taught to do the same, by hitting the spacebar twice after every period [full stop]. Your typing as well as your typesetting will benefit from unlearning this quaint Victorian habit. As a general rule, no more than a single space is required after a period, colon, or any other mark of punctuation .
10. Book: Schriver , Karen . Dynamics in Document Design: Creating Text for Readers . 1 . 1997 . Wiley . New York . 9780471306368 . 502 . Use one space (not two) after these punctuation marks [sc. period, question mark, exclamation point, or colon], as the practice of using two spaces is just another holdover from using a typewriter. .
11. Book: Strauss , Jane . The Blue Book of Grammar and Punctuation: An Easy-to-Use Guide with Clear Rules, Real-World Examples, and Reproducible Quizzes . 10 . 2007 . Jossey-Bass . 9780470222683 . 176 . Spacing with Punctuation . http://www.grammarbook.com/punctuation/spacing.asp . Rule 1. With a computer, use only one space following periods, commas, semicolons, colons, exclamation points, question marks, and quotation marks. The space needed after these punctuation marks is proportioned automatically. With some typewriters and word processors, follow ending punctuation with two spaces when using a fixed-pitch font. . 2010-04-25 . 2010-04-28 . https://web.archive.org/web/20100428035624/http://www.grammarbook.com/ . live .
12. Book: The GPO Style Manual . 30 . 2008 . The U.S. Government Printing Office . Washington . 9780160818127 . 469 . 2.49 Leading and spacing . http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2008_style_manual&docid=f:chapter2.pdf . A single justified word space will be used between sentences. This applies to all types of composition. . 2010-04-25 . dead . https://web.archive.org/web/20080831023726/http://www.gpoaccess.gov/stylemanual/ . 2008-08-31.
13. Book: MLA Handbook for Writers of Research Papers . 7 . 2009 . Modern Language Association . 978-0-87352-297-7 . 292 . FAQ: How many spaces should I leave after a period or other concluding mark of punctuation? . http://www.mla.org/style_faq3 . Publications in the United States today usually have the same spacing after a punctuation mark 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, most publishers' guidelines for preparing electronic manuscripts ask authors to type only the spaces that are to appear in print. . 2010-04-25 . 2011-02-28 . https://web.archive.org/web/20110228040437/http://www.mla.org/ . live .
14. Book: The Chicago Manual of Style . 7 . 2009 . University of Chicago Press . 9780873522977 . 292 . FAQ: How many spaces should I leave after a period or other concluding mark of punctuation? . http://www.mla.org/style_faq3 . Publications in the United States today usually have the same spacing after a punctuation mark 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, most publishers' guidelines for preparing electronic manuscripts ask authors to type only the spaces that are to appear in print. . 2010-04-25 . 2011-02-28 . https://web.archive.org/web/20110228040437/http://www.mla.org/ . live .
15. Web site: The Chicago Manual of Style Online (Q&A: One Space or Two?) . 2003 . University of Chicago Press . 2010-04-25 . The view at CMOS is that there is no reason for two spaces after a period in published work. Some people, however—my colleagues included—prefer it, relegating this preference to their personal correspondence and notes. I've noticed in old American books printed in the few decades before and after the turn of the twentieth century (ca. 1870–1930 at least) that there seemed to be a trend in publishing to use extra space (sometimes quite a bit of it) after periods. And many people were taught to use that extra space in typing class (I was). But introducing two spaces after the period causes problems: (1) it is inefficient, requiring an extra keystroke for every sentence; (2) even if a program is set to automatically put an extra space after a period, such automation is never foolproof; (3) there is no proof that an extra space actually improves readability—as your comment suggests, it's probably just a matter of familiarity (Who knows? perhaps it's actually more efficient to read with less regard for sentences as individual units of thought—many centuries ago, for example in ancient Greece, there were no spaces even between words, and no punctuation); (4) two spaces are harder to control for than one in electronic documents (I find that the earmark of a document that imposes a two-space rule is a smattering of instances of both three spaces and one space after a period, and two spaces in the middle of sentences); and (5) two spaces can cause problems with line breaks in certain programs. So, in our efficient, modern world, I think there is no room for two spaces after a period. In the opinion of this particular copyeditor, this is a good thing. . 2009-01-05 . https://web.archive.org/web/20090105172745/http://www.chicagomanualofstyle.org/ . live .
16. Book: Publication Manual of the American Psychological Association (aka APA Style) . 5 . 2001 . American Psychological Association . Washington . 9781557987907 . 439 . Chapter 5. Manuscript Preparation and Sample Papers to be Submitted for Publication . 5.11 Spacing and Punctuation: Space once after all punctuation as follows: after commas, colons, and semicolons; after punctuation marks at the end of sentences; after periods that separate parts of a reference citation; and after the periods of the initials in personal names (e.g., J. R. Zhang). Exception: Do not use space after internal periods in abbreviations (e.g., a.m, i.e., U.S.) . 2010-04-25 . registration .
17. Book: Style Manual: for Authors, Editors and Printers (aka AGPS Style) . 6 . 2002 . Wiley Australia, The Commonwealth Government of Australia Printing Office . Stafford, Australia . 978-0-7016-3647-0 . 117 . In typewritten (as distinct from typeset) material, it was customary to place two spaces after a colon, semicolon, full stop or other sentence closing punctuation. 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. . 2010-04-25 . 2015-03-26 . https://web.archive.org/web/20150326021312/http://www.australia.gov.au/publications/style-manual . dead .
18. Book: Mergenthaler Linotype Company. Linotype Keyboard Operation: Methods of Study and Procedures for Setting Various Kinds of Composition on the Linotype. 1940. Mergenthaler Linotype Company. Mer40. cited in Web site: Double-spacing after Periods. Mark Simonson. 5 March 2004. Typophile. 5 April 2010. 20 January 2010. https://web.archive.org/web/20100120091711/http://typophile.com/node/3466. dead.
19. Book: Felici, James. The Complete Manual of Typography: A Guide to Setting Perfect Type. 2003. Peachpit Press. Berkeley, CA. 0-321-12730-7. 80.

    Book: Fogarty, Mignon. Grammar Girl's Quick and Dirty Tips for Better Writing (Quick and Dirty Tips). 2008. Holt Paperbacks. New York. 978-0-8050-8831-1. 85. ; Book: Straus, Jane. The Blue Book of Grammar and Punctuation: An Easy-to-Use Guide with Clear Rules, Real-World Examples, and Reproducible Quizzes. 10th. 2009. Jossey-Bass. San Francisco, CA. 978-0-470-22268-3. 52.

20. Book: Bringhurst, Robert. The Elements of Typographic Style. 3.0. 2004. Hartley & Marks. Washington and Vancouver. 0-88179-206-3. 28, 30.
21. News: Hamblin. James. The Scientific Case for Two Spaces After a Period. 14 May 2018. The Atlantic. 11 May 2018. 14 May 2018. https://web.archive.org/web/20180514150447/https://www.theatlantic.com/science/archive/2018/05/two-spaces-after-a-period/559304/. live.
22. Book: The International System of Units (SI) . International Bureau of Weights and Measures . International Bureau of Weights and Measures . 149 . 2019 . 9th . 2023-01-13 . 2023-01-13 . https://web.archive.org/web/20230113090424/https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf/ . live . .
23. Book: The International System of Units. 9th. International Bureau of Weights and Measures. 2019. 978-92-822-2272-0. 150. 2019-11-13. 2021-10-18. https://web.archive.org/web/20211018184555/https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf/fcf090b2-04e6-88cc-1149-c3e029ad8232. live.
24. Web site: SCC 14 Conventions for Metrication of IEEE Standards. 2017-10-31. IEEE. 2019-11-12. 2019-07-23. https://web.archive.org/web/20190723192955/https://standards.ieee.org/content/dam/ieee-standards/standards/web/governance/revcom/scc14.pdf. live.
25. Web site: 2022-07-18 . Writing and formatting IEC . live . https://web.archive.org/web/20220718143708/https://www.iec.ch/standards-development/writing-and-formatting . 2022-07-18 . 2022-07-18 . International Electrotechnical Commission.