The dash is one of the youngest punctuation marks but it is unclear as to when the dash came in to common use, some note that it only really started to appear from the eighteenth century onwards.
Most commonly known are the en dash (–) and the em dash (—). As they sound so similar—in the printing industry—they were given nicknames. The en dash is known as ‘nut’ and the em dash is known as ‘mutton’.
The en dash is approximately the width of
a typesetter’s letter “N”. It is used to indicate a closed number range or to make a connection between two words. The em dash is approximately the width of a typesetter’s letter “M”. It indicates a pause before continuing and it can introduce an explanation or signify an abrupt change.
No other punctuation mark seems to have caused so much heated discussion amongst typographers. Is it an en or an em dash?