It’s best to break up lengthy passages into concise sentences. However, if you feel the need to parenthetically interject an explanatory or qualifying remark, our style is to use the en-dash (with a space on either side) rather than the longer em-dash.
The en-dash is also best for indicating a range, like January – May or Pages 7 – 13.
To insert an en dash in Microsoft Word, use Insert>Symbol. Or use the following method to convert a hyphen to an en dash: Word(Space) – Word(Space).
If you prefer keyboard shortcuts, on a Mac, opt-hyphen will create an en dash. The Windows shortcode is Alt-0150.