Have you ever wondered when to use an em dash or a colon within a sentence? What’s the difference, if any? Well, it really depends on how you want to present your information. Have no fear—I’m going to show you when it’s appropriate to use each of these pesky forms of punctuation so you can feel more confident when writing.
There are three ways to use a colon within a sentence: 1) in-sentence lists, 2) bulleted lists, and 3) pointing.
Ha! I just showed you an example of setting up an in-sentence list with a colon, but here’s another one so that you can see it more clearly:
Before I can go to The Wizarding World of Harry Potter in Orlando, I have to: 1) save up enough money for a ticket, 2) request specific days off at work, and 3) buy a suitcase.
You might be thinking: “Can’t you just list those items normally with commas?” Yes, reader; you can. However, setting up an in-sentence list like this creates emphasis on the list itself. You can use a colon before an in-sentence list when the list is the most important part of your sentence. Also, the numbers before each item are optional, but I would recommend them if each item in your list is longer than five words (or if any of the items in your list contain any of the FANBOYS conjunctions: for, and, nor, but, or, yet, and so).
In-sentence lists are used more in formal writing. If you’re wanting to put lists into informal writing, you can use a bulleted list, like this one:
Marvel Studios, which famously adapts popular Marvel comics into film, has announced the production of the following films that are set to be released within the next four years:
- Doctor Strange
- Guardians of the Galaxy 2
- Thor: Ragnarok
- Avengers: Infinity War Part I
- Black Panther
- Captain Marvel
- Avengers: Infinity War Part II
Be sure to include the colon at the end of the phrase before you insert a linebreak to start your bulleted list. If you’re trying to decide whether to use an in-sentence or bulleted list, bulleted lists are great for lists that are more than five items long. It would be daunting to read all of those movies in the same sentence, right?
The last way is pointing. Pointing is when you want to establish a close relationship with another part of the sentence by “pointing” to it with a colon. For example:
There’s really only one way to describe my brother’s room: a mess.
See? The colon is used here to emphasize your main point by establishing a close relationship. One of the great things about colons is that they’re optional; there are many other ways you can use emphasis in your papers. There’s no need to force them into a sentence, but hopefully knowing these rules will allow you to be more confident when using colons. The tutors at the Writing Resources Center are also happy to help you decide what type of punctuation works best within your sentence-in-question.
Now, onto dashes!
There are several types of dashes out there, which makes the whole usage thing frustrating. The types of dashes are defined by size. I’m going to show you how to use an em dash—the one you use within a sentence—so that you can be better prepared for your academic endeavors. If you’re interested in how to use the en dash—which is smaller than an em dash—you can find more information here. There are three ways to use an em dash in a sentence, and they can be remembered with “PAL”—pointing, appositives, and lists.
Just like colons, em dashes can be used to emphasize the main point of your sentence by “pointing” to it. However, colons establish a closer relationship than dashes do. Here’s an example of pointing with an em dash:
There’s only one thing I want from you—an RSVP to my S Club party.
Like the example of pointing with a colon, the em dash is used to “point” to the most important part of your sentence. However, the em dash is arguably less formal than a colon in this context. You’ll notice that there are no spaces on either side of the em dash—it physically connects the phrases on either side of it.
You can also use em dashes for appositives within sentences, which are casually referred to as “asides.” Appositives are phrases that sort of interrupt a sentence to give you more information or provide clarification. Here’s an example:
The season premiere of Game of Thrones—which is my favorite show—airs on April 24, 2016.
The appositive is found between the two em dashes in this example. The sentence would still be a complete, coherent sentence without the appositive—The em dashes here act as an interruption.
The last way to use an em dash is in an in-sentence list, which is structured similarly to the in-sentence list of a colon.
When I visited the World of Coca-Cola in Atlanta, I got to sample how Coke tastes in various countries—Japan, France, Australia, Canada, and many more.
The Final Countdown: Em Dashes vs. Colons
Before I leave you, you may have noticed that colons and dashes can be used in similar ways. Don’t forget that a colon establishes a closer relationship to the sentence than a dash does. Think about how Turk and J.D. from Scrubs are such good friends that they’re never apart and they’re practically the same person. They’re so close that they complete each other: that’s a colon relationship.
Now think about how Michael and Dwight from The Office (U.S.) are friends (and work together), but you wouldn’t call them best friends. Dwight idolizes Michael and jumps at the chance to spend time with him in any way, but Michael only really comes to Dwight when he needs something. You could even say that Michael keeps Dwight at arm’s length (with some exceptions). They’re connected, but not as connected to each other as Turk and J.D.—that’s a dash relationship.
Phew! That was a lot of information, but I can tell you’ve absorbed it all. Keep in mind that since the use of em dashes and colons are optional, it’s important to be wary of how many you use in a single paper. A happy paper has a balance of punctuation (em dashes, colons, commas, semicolons, etc.). Still not as confident as you’d like to be? The Writing Resources Center is here to help guide you through those pesky punctuation decisions. Make an appointment today!
You can also check out these great resources to refer to when you come across dashes and colons within a sentence (and outside a sentence too!):
- The University of Minnesota discusses hyphens and dashes: http://writing.umn.edu/sws/quickhelp/punctuation/hyphensdashes.html
- Purdue University discusses hyphens and dashes: https://owl.english.purdue.edu/engagement/3/7/98/
- UNC Chapel Hill discusses semicolons, colons, and dashes: http://writingcenter.unc.edu/handouts/semi-colons-colons-and-dashes/
- Georgia College discusses commas, semicolons, colons, and question marks: http://www.gcsu.edu/writingcenter/punctuation-rules
- Suny Empire State College discusses colons: https://www.esc.edu/online-writing-center/resources/punctuation/colons/
Good luck and happy writing!