Dashes and hyphens are easy to get mixed up. Dashes are longer than hyphens and have different uses. Hyphens are mostly used to connect two-part words.
Not: She worked for a non–profit organization.
But: She worked for a non-profit organization.
We use dashes instead of commas and parentheses when we want to provide more emphasis.
When the committee discovered the errors – all nine of them – they asked for a new draft.
When you’re writing about a span or range of numbers, dates or time, use “to” rather than a dash.
Not: Please read pages 11–17 in the report.
But: Please read pages 11 to 17 in the report.