In lots of writing, the use of dashes is very inconsistent – regardless of how ‘professional’ the writers are.

The hyphen, dash, n-dash and m-dash crop-up all the time in Microsoft Word but most of us don’t know why, and we use them inconsistently. The fact is that the n-dash and m-dash are very useful and easy to use – whether you follow the rules or break them (but it’s best to break rules consistently).