Em dash, en dash, hyphen — which to use?

Em dashes, en dashes, hyphens.

Three horizontal bars of punctuation, of different lengths, but which to choose for which job?

If you’re anything like me, you might typically use guesswork (on a good day) or impatiently plump for the hyphen (on a bad day), but this is hardly ideal, is often incorrect, and just makes work for a conscientious copy editor.

So here’s a quick guide.

The Em Dash (—)

When to use it

You can use the longest of the three punctuation marks, the em dash, as you might use a colon, to introduce a short list, and also to signify emphasis towards the end of a sentence, typically of a single word.

There are three punctuation marks considered in this article — the em dash, the en dash, the hyphen.

After a long day of writing, and editing, and more writing, and more editing, there was only one thing for it — wine.

You can use a pair of em dashes as you might a pair of commas or brackets in a sentence. This is particularly useful when the sentence is itself quite long, as it can facilitate reading and understanding.

Once he had finally settled on using the em dash in the troublesome sentence—mostly because he decided that it was the most stylish option—and filed the finished article to his editor, he resolved to use it even more in future, especially in preference to the colon.

Using em dashes here I think emphasises the text between them, whereas commas would give the content slightly less importance, and brackets less still. At least, that’s how I use them, but other writers may use them to contain a more ‘throwaway’ remark in more informal writing.

A final point:

Note that some publishers — typically newspapers — prefer to use a space before and after each em dash, as shown in this sentence, but others prefer no spaces, as shown in the example above.

Where to find it

On various programs, you can choose it via the Insert, Character options. There are keyboard alternatives, which may or may not always work, depending on which program or text editor you’re using:

On a Mac:
a/ Hold down the Shift and Alt/Opt keys and hit hyphen (typically to the right of the 0)
b/ Hit hyphen twice, then spacebar

On a PC:
a/ Hold down Alt key and type 0151 on the number keypad
b/ Hold down Ctrl and Alt keys and hit minus sign on the number keypad

The En Dash (–)

When to use it

The main use is in a span of numbers, such as a period of years, or sports scores, or other numerical ranges, including in the indexes of books.

Cardiff City thrashed Real Madrid 7–1 in the 2018–19 Champions League final.

Strictly speaking, you can use it to replace the word ‘to’, but not if you introduce the span with the word ‘from’. So:

If you need advice on punctuation, chapters 2–4 are essential reading. (Correct)

I worked as a freelance writer and translator from 1998–2014. (Incorrect)

Similarly, if you introduce the span with the word ‘between’, you should use the word ‘and’ between the numbers, not an en dash.

A use of which I wasn’t aware until I wrote this blog was in forging a connection between words to represent a span of distance or period, or indeed a conflict or duopoly.

The magazine is published quarterly, with the January–March 2019 edition now being commissioned.

Which has the greater impact on the British economy — the left–right political divide or the north–south geographical one?

Where to find it

On a Mac:
a/ Hold down the Alt/Opt keys and hit hyphen (typically to the right of the 0)

On a PC:
a/ Hold down Alt key and type 0150 on the number keypad
b/ Hold down Ctrl key and hit minus sign on the number keypad

The hyphen (-)

When to use it

A hyphen has multiple uses, but mostly its purpose is to join words. Just a few examples:

For compound adjectives, for example: a run-of-the-mill idea, an off-the-peg suit
For compound numbers: twenty-nine, sixty-three, seventy-two
To present an age: a seven-year-old girl
For fractions: two-thirds of the share
When using prefixes with nouns: post-Christmas sales in mid-January

It can also be used to clarify or aid legibility — such as in the words re-enter or de-ice — or prevent ambiguity between words — such as re-cover versus recover and re-press versus repress (to mean ‘cover again’ and ‘press again’, respectively).

Another often-quoted example is black-cab drivers versus black cab-drivers.

Where to find it

On your keyboard, to the right of the zero, usually.