This week, I wanted to pick up on a small point from last week’s entry about how my use of punctuation differs from what Grammarly considers correct. I’m focussing not on commas, but hyphens and dashes.
There are three main lengths of horizontal line used as punctuation in English. The shortest of these is the hyphen (-), the mid-length is called an en-dash (–), and the third is an em-dash (—). For the purposes of this entry, we’ll ignore the underscore (_) as this is used only for computer programming and other specialist purposes. Now let’s look at how these three marks are used.
A hyphen connects two words or two parts of words together, and touches the letters on either side. It’s done to avoid ambiguity or to suggest a certain pronounciation.
Consider how, ‘I re-sent your e-mail’ communicates something very different from ‘I resent your e-mail.’
You might also note that ‘e-mail’ is hyphenated here, indicating that the stress should be placed on the first syllable. The more common form these days is ’email’, but modern readers understand the pronounciation without the hyphen as a guide.
A hyphen can also be used to show a range; eg, ‘The Hundred Years’ War: 1337-1453′.
This takes its name from the width of the letter ‘n’ in the first printing presses, although the width varies on modern machines, and it has several uses.
It can be used as an alternative to the hyphen to show a range; eg, ‘Normal core body temperature: 97–99˚F’. But that’s the only crossover in usage.
On this blog, I frequently use the en-dash in place of brackets – to interrupt one thought with another – and you can easily find them in previous entries. In this case, the dash doesn’t touch the letters that surround it.
You don’t even need to come back to the original thought, as an en-dash will quite happily take the reader in a different direction – and leave them there.
The em-dash takes its name from the width of a letter ‘m’. Like the en-dash, this punctuation breaks up a sentence, but with more urgency.
Recently, I wrote in a comment, ‘There were two blunders—sorry, happy accidents—in the pictures below.’ I could have used en-dashes there, but this construction implies a slightly frantic energy. The em-dash always touches the letters that surround it.
Unlike the en-dash, however, this punctuation mark isn’t suitable for showing a range.