Em dashes are abrupt. They stand out, demand recognition and alert readers that the words to come are important. Em dashes are bold and sometimes unsettling, loudly ushering parenthetical statements into a sentence.
Consider them party crashers—immensely popular ones.
What should the em dash look like?
The examples all show em dashes edged against the words they separate. Two prominent grammar guide books, The Chicago Manual of Style and The Oxford Guide to Style, advocate this style.
Meanwhile, The New York Times Manual of Style and Usage and Associated Press both insert spaces between the em dash and the words it separates. Ragan goes with the Chicago style; either way is fine.
The em dash should always look like one continuous line (—), not two separate dashes (–). Before there was desktop publishing the em dash was two separate dashes because typewriters didn’t enable writers to create the smooth, single line.
Join the em dash discussion on MyRagan.