Em dashes are used to separate parts of a sentence, especially when there is an abrupt change from one clause to another, or if special emphasis is required when adding information to an existing clause. See the following sentence for an example:
Greek infantry, based on the hoplite—the heavily armed and armoured infantryman organized into tight phalanxes—replaced the horseman as the decisive force on the battlefield. (Lerner 1986, p. 202)
In the above sentence, the em dashes are unspaced, which is the style favoured in North American usage. In this example, the dashes are used to set off the separate clause, ‘breaking’ it out of the main sentence. Parentheses (brackets) could also have been used, but would give less importance to the set-apart text.
British publishing prefers to use a spaced en dash for the above application:
The first half of the Fields seems to have been reserved for laundresses, to dry their washing, and you would not be popular if you – or your dog – trod on the linen spread out on the grass. (Picard 2003, p. 92)
The Australian Style Manual recommends using an unspaced em dash in Australian government publications, avoiding confusion with the spaced en dash.
The em dash also conveys a sudden change of focus in a sentence, or the addition of an explanation:
The stronger term of various dualist oppositions is in Plato’s work valorized through the use of what Derrida calls a “supplement”—here, writing, called a pharmakon, both poison and cure.(duBois 1988, p. 170)
Em dashes should be used sparingly in your writing.
En dashes are used in the opposite way to em dashes. Where em dashes divide, en dashes unite. En dashes are commonly used to indicate spans of numbers, times and distances:
- pages 54–67
En dashes can attach words to each other, while maintaining the separate identity of each word:
They can link prefixes to more than one following word:
- pre–contact Indigenous Australia
- non–English speaking background
En dashes are used in compound adjectives that are made up of more than one word on either side of the dash:
- an extravagant Bollywood–style wedding
En dashes are also used as minus signs. They are used with a space in minus operations:
- 50 – 10 (50 minus 10)
When indicating a negative number, the en dash is used without a space:
- –20 degrees (temperature)
To use these punctuation symbols effectively in your writing you might like to set up a ‘style sheet’ where you have copied and pasted these symbols. When you need to insert the symbol in your text, refer to your style sheet, copy from it and paste directly into your text. Otherwise, you will need to click on the ‘Insert’ tab in MS word (2010), and then open ‘Symbol’ on the extreme right of your screen. You will then need to click on ‘More symbols’ and ‘Special Characters’ where you will find em and en dashes, plus the correct em and en spaces to use with them. Highlight your choice and click ‘Insert’. This box can remain open while you insert what you need. When you have finished, close the box. This symbol list also shows you shortcut key options, which may be more efficient if you are using many en dashes in a reference list.
- duBois, P 1988, Sowing the body: Psychoanalysis and ancient representations of women, University of Chicago Press, Chicago.
- Lerner, G 1986, The creation of patriarchy, Oxford University Press, New York.
- Picard, L 2003, Elizabeth’s London: Everyday life in Elizabethan London, Phoenix, London.
- Snooks & Co, 2003, Style manual for authors, editors and printers, 6th edn, John Wiley & Sons, Brisbane.
Updated 23 October 2018