Back in the days when type was set in lead, the use of hyphens, en rules and em rules was well understood by typesetters and considered important.
Word, Google Docs and HTML all provide facilities for differentiating between these three forms of punctuation, but it’s clear that many people either don’t understand or appreciate the differences, or perhaps they do but don’t know how to insert them.
This guide will try to help you understand the differences in use and also how you can insert them when you type.
What is a hyphen, en rule and em rule?
They are all types of dashes in a sense (‘rule’ here refers to a line type ‘rule’, not a regulation type ‘rule’).
An en rule is slightly longer than a hyphen and an em rule longer than an en rule. The terms ‘en’ and ’em’ originally referred to the length of the lowercase ‘n’ and uppercase ‘m’ character in a typeface. The terms en rule and en dash (or em rule and em dash) are interchangeable. I prefer to say ‘rule’ rather than ‘dash’, as ‘dash’ can cause confusion (this should become clear soon).
– en rule
— em rule
A hyphen is used:
• To join a single word at a line break, though in publishing now this is usually avoided
• To join an adverb with an adjective to form a single concept, eg ill-advised, well-known, poverty-stricken, twentieth-century
• In some adjectives used attributively (before the noun they qualify), eg ‘up-to-date’, but not as a predicate (used after the noun). So: ‘the information is up to date’
• In fractions spelt out, eg ‘two-thirds’, ‘three-quarters’. Don’t use hyphens if the fraction includes ‘a’ or ‘an’, so: ‘half an inch’.
An en rule is used to indicate spans:
• To join two dates, eg ‘the 2014-15 financial year’
• Ages, eg ‘the 16–19 prospectus’. But write ‘students from 16 to 19’
• Joint authors, eg ‘The Smith-Wilson Report’
• Nouns of equal relationship, eg ‘The North-South divide’, ‘teacher-pupil ratio’
An em rule is used as a dash in sentences — you can see now why I find the term en dash confusing, as a dash is an em not an en! An em rule/dash is an alternative to parentheses or ‘brackets’.
A dash is often preferred to give a feel of movement, whereas parentheses often give the impression of slowing down the flow of the text.
Eg: ‘He rushed to town — using the opportunity to try out his new car — when he realised he had forgotten to buy a present for Mother’s Day’
How to insert hyphens, en and em rules
In the instructions below bear in mind that Windows and Apple Mac keyboards, and tablet and smartphone keyboards sometimes differ.
Microsoft Word and Excel
- The hyphen is on the main keyboard, usually on the top row to the right of zero.
- The hyphen is also usually in the top right corner of the numeric keypad.
- The en rule can be inserted using Ctrl plus the hyphen key on the numeric keypad
- The em rule can be inserted using Alt Ctrl plus the hyphen key on the numeric keypad
PowerPoint also has the Insert Symbol Ω option but without the keyboard shortcuts or Insert Symbol Special Characters option.
On GoogleDocs go to Insert Symbol/Insert Special Characters and select the drop down menus that give you Punctuation and Dash/Connector.
At the time of writing (July 2014) this doesn’t appear to be available in Google Spreadsheets or Presentations, but Google is constantly updating its Google Docs programmes so any of these instructions are prone to be updated as they add new features.
If you’re hand coding in HTML these characters can be inserted using:
More information: www.ascii.cl
To some people these differences may seem pedantic.
But in professional publishing visually they do make a difference. You may not notice the difference if someone gets it right. If they don’t follow these rules — especially if a page of text uses these symbols inconsistently — you will almost certainly feel that something is wrong.