The history of the em dash begins in the printing house. The mark is named after the em, a typesetter's unit of width, and early English plays printed it as a row of short strokes for a speaker cut off. Laurence Sterne stretched it across Tristram Shandy, Emily Dickinson's editors have printed hers differently since 1890, and style guides still disagree about its length and spaces.
EdCitation publishes this guide, built from a compositor's manual of 1901, a grammar of 1819, scholars of Sterne and Dickinson and the style guides' own pages, all read on 2 October 2026. Whether a dash signals AI is argued in the em dash is not proof of AI, not here.
EdCitation never writes any part of anyone's work, a line we hold with pride: every word and dash you hand in stays yours. Find sources finds the scholarship, and Mechanics QA checks a finished paper's formatting and the slips a spell-checker lets through.
What is an em dash, and why is it called that?
An em dash (—) is the long dash that sets off a break or an aside, named after the em, a printer's measure. AP's Stylebook editor puts it at about the width of a capital M, and the en dash (–) at half that, close to a capital N (Bratton, 2025). Houston (2025) adds that the em was once held to match the M of its typeface but now equals the type size: a 16-point font has a 16-point em dash.
Compositors set the dash to fill that whole width: De Vinne (1901) says it "entirely fills the body sidewise", and wants a thin space either side. The hyphen, shortest of the three, joins words, and alone has its own key on a standard keyboard (The Chicago Manual of Style, 2024).
When did printers start using dashes?
By the 1580s, in plays. Anne Toner's 2015 book Ellipsis in English Literature, as the University of Cambridge (2015) summarised it, finds the earliest case among her examples in Maurice Kyffin's 1588 translation of Terence's Andria, where three or four short dashes or hyphens show a speaker breaking off.
From playbook to page
Kyffin's translation has three such breaks; a 1627 translation of the same play has 29. In 1634 the schoolmaster John Barton wrote that playbooks marked them "thus ---", and in the First Folio's Henry IV, Part 1, in Toner's words, "Hotspur dies on a dash". Who chose a given dash is often unclear, because authors were encouraged "to leave punctuation marks to printers" (University of Cambridge, 2015).
The dash on trial
Jonathan Swift rhymed "dash" with "printed trash", and Henry Fielding named a hack writer Dash. Lindley Murray's English Grammar of 1795 still placed the dash among the main marks, warning against its use by "hasty and incoherent writers" (University of Cambridge, 2015). Cobbett (1819) replied that the dash was "a cover for ignorance as to the use of points", and asked for rules on its length: the inch, the three-quarter-inch, the half-inch.
De Vinne (1901) quoted Cobbett and disagreed: the dash had been "a useful mark of punctuation in Great Britain and America for at least two centuries". The manual's rules are a typesetter's: no dash at the start or end of a line if avoidable, and no dashes "of two ems or more" to mark a break.
How did Sterne use dashes in Tristram Shandy?
Constantly, and in more than one length. Tristram Shandy appeared in nine small duodecimo volumes, in five instalments from 1759 to 1767, its text "interlarded with longer and shorter hyphens", as the Sterne scholar Peter de Voogd (2018) puts it. Mullan (2002) reads those "stretched dashes" as the narrator "changing his mind, pausing for pathos or innuendo".
One em or two
De Vinne (1901) saw a system: an em dash for a short break, a two-em dash for a long one. The manual reprints the lines on Le Fever's death as "a close reprint" of Sterne's punctuation: "the pulse fluttered,—stopped,—went on". Project Gutenberg's transcription of the same lines reads "the pulse fluttered——stopp’d——went on", without those commas (Sterne, 1759–1767/1997). Both cannot follow Sterne exactly, and we could not see a first edition of that volume, so which is closer is unconfirmed.
What a modern edition cannot show
De Voogd (2018) describes the original page, a text area of 11 by 6.5 cm in twelve-point type, and argues that no single-volume paperback can give its effect. De Voogd's article works from the Florida Edition text, edited by Melvyn and Joan New in 1978. In an essay, quote the edition your module names, dashes as printed.
Why are Emily Dickinson's dashes so debated?
Because her manuscripts and her printed poems do not match, so every editor must decide what her marks are. Her poems were published in full only after her death, and Harper (2019), editor of the Chicago Manual's online Q&A, describes her handwritten dashes as more like spaced hyphens.
How each edition prints them
| Edition | How the dashes appear | Source |
|---|---|---|
| Poems, edited by Todd and Higginson, 1890 | In "Because I could not stop for Death", line-end dashes became a semicolon and a full stop | Harper (2019) |
| The Poems of Emily Dickinson, edited by Johnson, 1955 | Spaced en dashes | Harper (2019) |
| Franklin's variorum, 1998, and reading edition, 1999 | Spaced hyphens, closer to her hand | Harper (2019) |
| Emily Dickinson's Poems: As She Preserved Them, edited by Miller, 2016 | Dashes in other people's copies made to look like the shorter dashes she generally wrote | Miller (2016) |
What the scholars argue
The quarrel is over whether the shape of a dash carries meaning. Crumbley's publisher sums up the book's case (Crumbley, 1997): her manuscript dashes "vary tremendously in length, height, and angle", and mark shades of inflection and more than one voice. Mitchell (2001) set out to test claims of that kind against the spacing, direction and letter shapes of her poems and letters. Miller (2016) judges that writing the poems out was of "secondary importance to her play with language".
For an essay, quote one edition and name it in your reference. Find sources, asked for "Emily Dickinson dash", returned 953 results, with a review of Crumbley's Inflections of the pen: dash and voice in Emily Dickinson first and Kamilla Denman's "Emily Dickinson's Volcanic Punctuation", from 1993, twelfth; Denman's page asked for a verification check we do not pass, so we report nothing of it. From Mitchell's DOI, Cite a source returned, in MLA 9:
Mitchell, Domhnall. “The Grammar of Ornament: Emily Dickinson’s Manuscripts and Their Meanings.” Nineteenth-Century Literature, vol. 55, no. 4, Mar. 2001, pp. 479–514, https://doi.org/10.1525/ncl.2001.55.4.479.
Em dash vs en dash vs hyphen: what do the style guides say?
They agree on the hyphen and on the en dash in ranges, and split over the long dash: Chicago and APA close the em dash up, AP spaces it, and the Guardian and the University of Oxford use a spaced en dash.
| Mark | Use | Example | Source |
|---|---|---|---|
| Hyphen | Joins a compound word or modifier | a low-anxiety group; an up-to-date list | Lee (2013); University of Oxford (n.d.) |
| En dash, closed | Ranges of numbers and pages | pp. 34–36; 3–5 | American Psychological Association (2022); The Chicago Manual of Style (2024) |
| En dash, closed | Two items of equal weight | test–retest reliability; German–Polish non-aggression pact | Lee (2013); University of Oxford (n.d.) |
| En dash, closed | A compound built on an open compound | pre–Civil War | The Chicago Manual of Style (2024) |
| En dash, spaced | A break or a pair of dashes, British style | A single dash can add a touch of drama – like this. | The Guardian (2021) |
| Em dash, closed | A break or an aside | at the end of a sentence—like this one | McAdoo (2010); The Chicago Manual of Style (2024) |
| Em dash, spaced | AP's abrupt change or emphatic pause | have adapted — usually skillfully — to | Bratton (2025) |
| 2-em dash | Letters or words missing from a quotation | Admiral N—— | The Chicago Manual of Style (2024) |
The long dash: closed, spaced or en
Chicago closes the em dash up, and notes that British style more often uses spaced en dashes (The Chicago Manual of Style, 2024). APA's blog, writing for the sixth edition and read in an archived copy, quoted the manual: the em dash sets off an element "added to amplify or to digress from the main clause", and overuse "weakens the flow of material" (McAdoo, 2010). The seventh edition's section on dashes is in the printed manual, which we could not read; APA's site today uses en dashes in page ranges (American Psychological Association, 2022).
AP's dashes "always get a space on either side, except in sports agate", and AP has historically done without en dashes, which did not reach newspapers correctly over teletype (Bratton, 2025). The Guardian (2021) wants spaced en dashes, used sparingly. Oxford speaks with two voices: the University of Oxford (n.d.) says of the em dash "Do not use", while Oxford University Press (2014) tells its reference authors to key three hyphens for a parenthetical statement, and closes up its own em dashes. The two Oxfords part over the Oxford comma too.
When should you use an em dash in an essay?
Use one for a sharp break or an aside you want noticed, and use few: APA, AP and the Guardian all warn against overuse. In order:
- Find your style. Paste the brief into EdCitation's free Check your paper, which lists the citation style beside the sentence that names it.
- Set the long dash that style's way: closed em dashes for Chicago and APA, spaced em dashes for AP, spaced en dashes for a house style like the Guardian's. Never mix two.
- Use en dashes for ranges and equal pairs, as in pp. 34–36 and test–retest. In references, let the style decide: for Mitchell's article, Cite a source joined the pages with an en dash in five styles and with a hyphen in Vancouver, the form our Vancouver guide describes.
- Keep hyphens for compound words: a low-anxiety group, an up-to-date list.
- Read each dash aloud. Where commas, brackets, a semicolon or a new sentence would do, AP and the Guardian both suggest them.
- Run the final checks: Mechanics QA for formatting and slips, and Verify references, free, for the list.
How did the em dash become a supposed AI tell?
Online, and with little evidence behind it. Bratton (2025) was not sure where the idea began, and pointed to Grammar Girl's suggestion that a fashion podcast had revived it by urging people to drop "the ChatGPT hyphen". Houston (2025), writing that August, dated the complaint to the past year or so, traced the name to a clip from the podcast LuxeGen, and found documentary evidence for it "quite thin on the ground". Two replies came in May 2025: the "am dash", a new mark needing a custom font, and noemdash.com, which swapped em dashes for spaced hyphens.
What the studies measured, and why one dash says nothing about one writer, is in the em dash is not proof of AI. The history above is the short answer: the mark now pinned on the machines is one compositors were setting for Sterne in 1759.
How can EdCitation help with the dashes in your paper?
By checking the paper around them. EdCitation never writes, rewrites or repunctuates any part of anyone's work; the dashes, like the sentences, are yours.
Mechanics QA, the read by rule
A style guide is a set of rules, down to the space beside a dash, as the table above shows, so the best last check for a paper that must follow one is a check made by rule. That is Mechanics QA: no model reads your paper, and every finding names the rule it broke and the fix. It checks font, size, spacing, margins, title page, headings and the reference list against the APA 7 student paper; finds comments, tracked changes, placeholders and template text left in the file; matches each citation to the list; and flags figures that disagree between sections and the slips a spell-checker lets through. Dashes are not on its published list of checks, so the choices in this guide stay with you.
Upload a Word document or a PDF and each finding is marked where it sits; the next run shows what you fixed. Mechanics QA is part of Pro, at $8 a month or $72 a year, and a free account can run three checks a month (pricing).
Quick questions
What is the difference between an em dash and an en dash?
The em dash (—) is the long dash for breaks and asides; the en dash (–) is half its length and joins ranges and equal pairs, as in pp. 34–36 or test–retest.
Why did Emily Dickinson use so many dashes?
No one can say for certain. Crumbley (1997) reads their varied handwritten shapes as shades of voice; Miller (2016) thinks the look of the page mattered less to her than her play with language.
Does APA put spaces around an em dash?
No. APA's own blog showed the em dash closed up, with two unspaced hyphens as the fallback (McAdoo, 2010). AP, a news style, is the guide that spaces it.
Does AP style use the en dash?
Historically, no. Bratton (2025) explains that en dashes did not reach AP's newspaper customers correctly in the teletype era.
Will EdCitation fix the dashes in my essay?
No. EdCitation never changes a word or a mark of your work. Check your paper, free, tells you which style your brief wants, and Mechanics QA, in Pro, checks the formatting.
References
- American Psychological Association. (2022). Direct quotation of material with page numbers. APA Style. https://apastyle.apa.org/style-grammar-guidelines/citations/quotations/page-numbers
- Bratton, A. J. (2025, August 27). The em dash: A valid punctuation mark – or artificial intelligence easy tell? AP Stylebook. https://www.apstylebook.com/blog_posts/24
- The Chicago Manual of Style. (2024, January 23). Hyphens and dashes: A refresher. CMOS Shop Talk. https://cmosshoptalk.com/2024/01/23/hyphens-and-dashes-a-refresher/
- Cobbett, W. (1819). A grammar of the English language, in a series of letters. Thomas Dolby. https://archive.org/details/grammarofenglish00cobbiala
- Crumbley, P. (1997). Inflections of the pen: Dash and voice in Emily Dickinson. University Press of Kentucky. https://books.google.com/books/about/Inflections_of_the_Pen.html?id=bJFaAAAAMAAJ
- De Vinne, T. L. (1901). The practice of typography: Correct composition. The Century Co. https://archive.org/details/practiceoftypogr00deviiala
- de Voogd, P. (2018). A singular stroke of eloquence: Tristram Shandy's typography. Nordic Journal of English Studies, 17(1), 74–84. https://doi.org/10.35360/njes.423
- The Guardian. (2021, May 21). Guardian and Observer style guide: D. https://www.theguardian.com/guardian-style-guide-d
- Harper, R. (2019, October 8). A dash of poetic license. CMOS Shop Talk. https://cmosshoptalk.com/2019/10/08/a-dash-of-poetic-license/
- Houston, K. (2025, August 29). The dash for AI. Shady Characters. https://shadycharacters.co.uk/2025/08/the-dash-for-ai/
- Lee, C. (2013, May 9). Punctuation junction: Hyphens, en dashes, and slashes. APA Style Blog. https://web.archive.org/web/20240911102718/https://blog.apastyle.org/apastyle/2013/05/punctuation-junction-hyphens-en-dashes-and-slashes.html
- McAdoo, T. (2010, September 30). Computer editing tip: Em dashes. APA Style Blog. https://web.archive.org/web/20250811075051/https://blog.apastyle.org/apastyle/2010/09/computer-editing-tip-em-dashes.html
- Miller, C. (Ed.). (2016). Emily Dickinson's poems: As she preserved them. The Belknap Press of Harvard University Press. https://www.hup.harvard.edu/file/feeds/PDF/9780674737969_sample.pdf
- Mitchell, D. (2001). The grammar of ornament: Emily Dickinson’s manuscripts and their meanings. Nineteenth-Century Literature, 55(4), 479–514. https://doi.org/10.1525/ncl.2001.55.4.479
- Mullan, J. (2002, June 6). Shandying it [Review of the book Laurence Sterne: A life, by I. C. Ross]. London Review of Books, 24(11). https://www.lrb.co.uk/the-paper/v24/n11/john-mullan/shandying-it
- Oxford University Press. (2014). Oxford University Press Academic Division guide for authors and editors: Oxford Paperback Reference [PDF]. https://www.oxfordreference.com/fileasset/files/QuickReference_AuthorGuidelines.pdf
- Sterne, L. (1997). The life and opinions of Tristram Shandy, gentleman. Project Gutenberg. (Original work published 1759–1767) https://www.gutenberg.org/ebooks/1079
- University of Cambridge. (2015, October 21). … dot, dot, dot: How the ellipsis made its mark. https://www.cam.ac.uk/research/features/dot-dot-dot-how-the-ellipsis-made-its-mark
- University of Oxford. (n.d.). Punctuation. University of Oxford style guide. https://www.ox.ac.uk/about/the-university/brand/style-guide/punctuation