Use a hyphen (-) to join compound words before a noun
Use a hyphen (-) in some compound modifiers
Use a hyphen (-) with certain prefixes and suffixes
Use an en dash (–) to show ranges, such as dates, times, and numbers
Use an en dash (–) to connect related items or equal relationships
Use an em dash (—) to set off a break in thought
Use an em dash (—) to add emphasis or an aside
Use an em dash (—) instead of commas, parentheses, or colons when needed
Use a dash consistently within the same document style
Avoid using dashes where other punctuation is clearer