1. To Emphasize
* Parentheticals: When you want to add a non-essential phrase or clause for emphasis, dashes can be more forceful than commas:
* Commas: The car, which was red, was parked in the driveway.
* Dashes: The car—which was red—was parked in the driveway.
* Setting off a phrase for special emphasis:
* Commas: I have a lot of hobbies, like cooking, reading, and playing video games.
* Dashes: I have a lot of hobbies—like cooking, reading, and playing video games.
2. To Create a Break in the Sentence
* To separate contrasting ideas:
* Dashes: He was a good person—except when he was angry.
* To introduce a list:
* Dashes: She had three favorite things—chocolate, cats, and sunsets.
3. To Indicate an Abrupt Change in Thought
* To show a sudden shift in the sentence:
* Dashes: He wanted to leave—no, he had to leave.
4. When You Need a Stronger Pause Than a Comma
* For a longer, more dramatic pause:
* Dashes: The storm was coming—the sky was dark, the wind was howling.
5. When You Have Multiple Commas in a Sentence
* To avoid confusion:
* Commas: The cat, which was black, and the dog, which was brown, were both very friendly.
* Dashes: The cat—which was black—and the dog—which was brown—were both very friendly.
Remember:
* Use sparingly: Dashes should be used with care, as too many can make your writing seem choppy or overly dramatic.
* Follow style guidelines: Always check the style guide you're using for specific rules and preferences regarding dashes.
In most cases, a comma will be the better choice. But when you want to add emphasis, create a stronger pause, or highlight a contrast, a dash can be the perfect tool.