Use—and Non-use—of Dashes and Hyphens (Part 1 of 2)

While dashes and hyphens are distinct—both in appearance and function—the confusion they create (among students and academics alike) justifies their treatment in the same article, albeit an article lengthened to a two-part exposé. Part one will cover the functions and uses of dashes, while part two will cover the far less rigid (and accordingly more complex) use of hyphens.


‘The dash—to put if formally—is a mark of separation stronger than a comma, less formal than a colon and more relaxed than parenthesis.’

–Mark Tredinnick, The Little Green
Grammar Book
 (2008), p. 159.

Strictly speaking, ‘the dash’ refers solely to the em rule: —. However, less conservative grammarians (including yours truly) take the term ‘dashes’ to encompass the aforementioned em rule and the shorter en rule: –. Both are favoured and flavoursome tools of the proficient writer—the inclusion of both types of dashes in a text is as much to serve the function of relaxing prose, as it is to express the manner of professionalism and ease in which the writer has transferred thoughts to paper.

Em Dash

Dr Lisa Lines explains how to use the em dash in one of her YouTube videos.

The em dash (or em rule) has three main uses:

  1. to introduce an explanatory aside or signify an abrupt change in the direction of the sentence
  2. to introduce an amplification or explanation (standing in for a colon or semi-colon)
  3. to set apart parenthetic elements (i.e. parenthetic use).

An em dash used singularly can be used as an explanatory aside at the end of a sentence, or affect an abrupt shift:

The works of Shakespeare are considered classics—indeed, I doubt that there are any here who have not read at least one of this works.

The city is falling afoul of rising property rates and deteriorating infrastructure—but the City Council is not concerned with these matters.

Similarly, a single em dash can be used to introduce a summary of a list detailed before it, or, like a colon, the em dash can itself lead into a list:

Linen tablecloths, silverware cutlery, white-gloved butlers and the heavy scent of lavender—all the trappings of an over-priced wedding were present.

The scene had my mouth agape in horror—wine-stained table cloths, scattered cutlery, drunken bodies attempting to stagger past one another and the white-clad bride tearfully presiding over the entire affair.

A pair of em dashes can enclose a phrase, clause or word mid-sentence, in the same manner as a pair of commas or parentheses (but, as stated by Mark Tredinnick, the effect is unique, placing emphasis on the isolated parenthetic expression):

The five of us—already unashamedly drunk—entered the party amidst much pomp and fanfare.

The trees—hardy, mature white oaks of European origin, planted before the construction of the manor house by the original property owner, Sir J.P. Pennington—hung majestically over the carefully arranged tables and elated party guests.

In this way, the em rule should be the preferred choice for phrases or words that are abrupt or expand on the preceding clause. Note, however, that using multiple pairs of em rules in one sentence can create confusion—instead, use a combination of punctuation (commas and parentheses). Case in point, the previous sentence.

By way of digression, there is also a 2-em rule, utilised:

  1. for omissions and sudden breaks (e.g. an interruption or a sentence deliberately left unfinished).

It was alleged that the defendant had threatened the plaintiff, Mr. H——, with a club.

I heard him say, ‘Give yourselves up or I’ll ——’.

  1. to avoid repetition in lists and bibliographies (when more than one work by an author or authoring body is listed).

Lines, LM 2015, ‘Representativeness and Positive Discrimination’, in Baker D-P (ed.), Key Concepts in Military Ethics, UNSW Press, Sydney, pp. 56–59.

——— 2012, Milicianas: Women in Combat in the Spanish Civil War, Lexington Books.

——— 2009, ‘Female Combatants in the Spanish Civil War: Milicianas on the Front Lines and in the Rearguard’, Journal of International Women’s Studies, vol. 10, pp. 168–187.

En Dash

We also have a video explaining how to use the en dash.

The en dash (or en rule) when considered next to the em dash is comparatively simple, though no less essential. The en dash is used to link and show association between words and numbers, its most common uses, per the Style Manual, being:

  • to show spans of figures, time and distance
  • to show an association between words that retain their separate identities
  • to link prefixes with what follows in certain circumstances
  • to join some types of compound adjectives
  • used for the minus symbol in mathematical settings.

The first of these is by far the most common use of the en dash: meaning ‘to’ between two series of figures:

pages 54–9

63–75 Palmerston Street

9.00 am–12 noon



Darwin–Adelaide railway

Note that the en rule is unspaced when linking one word or one set of numbers on either side (as seen above). If there is more than one word to be linked on either side, the en rule is spaced:

a Commonwealth – Western Australia agreement

65 BC – 115 AD

The second use of the en rule is to show association between words that retain separate identities (keeping in mind the spaced en rule if there is more than one word on either side):

teacher–student relationship

the Asia–Pacific region

New Zealand – Australia defence talks

Queensland – New South Wales rivalry

Where a hyphen is used to link a prefix to one word, an en rule is used to link a prefix to more than one word:

pre–World War One

post–Industrial Revolution

anti–animal cruelty stance

ex–vice president

A more complex use of the en rule is replacing the hyphen in a compound adjective (see part 2 for hyphens used in a compound adjective when preceding/qualifying a noun) when that compound adjective consists of more than one word on either side of the hyphen:

award-winning director           to         Academy Award–winning director

college-educated individual    to         private college–educated individual

The final use of the en rule is as a minus sign. The en rule is unspaced when attached to an individual number (i.e. a negative value), and spaced when used in an equation (i.e. as an operative sign):


47 – 8 = 39

s = 5 x 10(4 – 3)

Ultimately, dashes—the en rule and the em rule—are crucial elements of punctuation that shape text as much as they communicate the skill and confidence of the writer who utilises them. To ignore the dashes is to forgo an essential part of the English language and an invaluable tool of expression. If possible, always consult your relevant style guide. Failing that, this grammarian is always keen to resolve any issue with the English language.

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