What is the difference between a hyphen, en dash and an em dash?

Dave Harland loves a good em dash. He doesn’t hold back.

As LinkedIn’s most prolific copywriter and a bonafide human being (a fact I believe has been authenticated), he professes that he can spot AI-generated "slop" from an em dash distance away.

However, as an old-school graphic designer with a penchant for typographic marks, I find myself in an embarrassing predicament. I love using an em dash — especially at the end of a sentence or as an interjection mid-sentence.

What am I to do?

Every time I write something, I live in fear that Dave will send his Uncle around to sort me out. That man has had more jobs than I've had hot dinners — I'm sure Punctuation Police is one of them!

At this juncture, if you find yourself asking, “What the hell is an em dash?”, then let me explain the difference between these seemingly innocuous typographic marks:

Hyphen (-)

The hyphen is the shortest of the three marks.

It links compound words (e.g., hands-on, editor-in-chief), indicates a word break at the end of a line, or is used in phone numbers and some dates.

En dash (–)

The en dash gets its name from the fact that it is typically the same width as the character n. It is used to indicate a range of values (e.g., pages 0–9), or for a connection between two things, such as a place (the London–Manchester line), or a double-barrelled name (Neville–Jones).

Em dash (—)

Can you guess how the width of the em dash is determined? Yup. It is the width of the character m—which is typically wider. It represents an abrupt change of thought, a sharp transition, or sets off an emphatic clause within a sentence.

To avoid confusion between the 'en' and 'em' dash, they can also be referred to as the 'nut dash' and 'mutton dash' respectively.

Should you add a space before and after a hyphen en dash, em dash?

Strictly speaking, you should never add a space before or after hyphens, an en dash, or an em dash. However, I do add a space before and after an em dash.

It is typographically incorrect, but it looks better to me, and here in the UK it is a common practice. UK publishers and certain academic styles typically use the spaced em dash.

Keyboard olympics

Accessing these marks can require some serious finger gymnastics. 

The keyboard shortcuts on a Mac are as follows:

• Hyphen: it to the right of the number 0 at the top of the keyboard.
• En dash: use the hyphen + option key.
• Em dash: use the hyphen + command + shift key.

The keyboard shortcuts on a Windows are as follows:

• Hyphen: it to the right of the number 0 at the top of the keyboard.
• En dash: Alt + 0150 (numeric keypad required).
• Em dash: Alt + 0151 (numeric keypad required).

Important note for Windows users

The standard Alt codes (Alt + 0150 and Alt + 0151) only work if you have a full numeric keypad on the right side of your keyboard. The number row across the top of the keyboard will not work for these shortcuts.

A parting word

There are a number of different typographic marks which we will explore in other articles, but at least you now know that the width of your dash really does matter.

Oh, and just in case Dave does read this: I may be a human that sounds like AI, but there is blood coursing through my veins. I think!