The dash is a piece of punctuation that you probably don’t use frequently in everyday life but which appears all the time on the SAT and ACT.
So, how do you use dashes, and—more importantly—how do you correctly answer exam questions that involve dashes?
You can use dashes either singly or in pairs. In either case, however, when dashes are used on standardized tests, their purpose is to set off non-essential information from the rest of the sentence. Let’s look at an example that uses a pair of dashes:
The students were happy to explore Paris—complete with its beautiful churches, monuments, and museums—and practice French with locals.
In this case, “complete with its beautiful churches, monuments, and museums,” while certainly providing accurate information about Paris, is not grammatically or contextually essential to the rest of the sentence. In other words, we could delete everything between the two dashes and the sentence would still work:
The students were happy to explore Paris and practice French with locals.
In fact, that’s the easiest way to understand the use of double dashes on the ACT or SAT. If you delete everything between the two dashes and the rest of the sentence still makes sense, the dashes are almost certainly correct.
Standardized exams alternate between using two commas and using two dashes to signify that the information is non-essential. While each usage is valid, you must be consistent. Use two dashes or two commas to set off a phrase: do not use one of each.
If a sentence uses only one dash, then everything after that dash must be non-essential information. Here’s an example of a sentence that correctly uses only one dash:
The students also enjoyed some of the fabulous pastries available in the city—specifically, the croissants and pains au chocolate.
In this case, if you were to delete everything after the dash, you would still be left with a complete sentence.
Ready to try a question on your own? Take a quick look at the sample ACT question below and see whether you can identify the correct answer using the rules above.
1. Allison enjoyed studying for Art History—her favorite class, because she was able to learn about Picasso and Monet.
A. NO CHANGE
B. class because she was able to learn
C. class—because she was able to learn
D. class; because she was able to learn
If you spotted the fact that the phrase “her favorite class” provides unnecessary information and could therefore be set off by a pair of dashes, then well done! Note too that the use of a dash to end the non-essential information is consistent with the use of a dash to begin it. Therefore, the correct answer is choice C.