1. To set off a parenthetical phrase:
* The dog – a fluffy, golden retriever – barked excitedly at the mailman.
* I tried to call her – several times, in fact – but she didn't answer.
2. To introduce an abrupt change in thought:
* I wanted to go to the beach – but it was raining.
* He promised to be there at 7:00 – or at least that's what he said.
3. To emphasize a word or phrase:
* He was the only one who could – and would – save the day.
* This is the best – and maybe only – chance we have.
4. To separate items in a list:
* She packed her bags with essentials – sunscreen, sunglasses, a good book – and set off on her adventure.
5. To indicate a range or span:
* The conference will take place from June 15 – July 1.
* The restaurant is open 11:00 am – 10:00 pm daily.
Remember:
* You can use either em dashes (—) or en dashes (–) depending on the context and style guide.
* A single dash can be used to indicate an interruption in a thought. For example: "I was about to go to the store –"
* Use spaces around dashes, unless your style guide specifies otherwise.