When to Use a Comma to Separate Phrases — and Other Comma Questions

By Carolyn, IvyWise College Admissions Counselor

In eighth grade, my English teacher Mrs. Houlihan told me that I was the only student in my class who knew how and when to use a comma. That feedback stuck with me, not just because it made me feel like the greatest student of all time (which, let’s be honest, I totally was), but because it made me realize the awesome power of the comma. For such a tiny piece of punctuation, the comma packs a mighty punch, in that using it correctly or incorrectly is one of the most glaring signs that a writer either does or does not know what they’re doing.

Nowhere is this more evident than in college application essays. A well-punctuated essay reads clearly and smoothly, while an essay with missing or incorrect punctuation causes the reader to notice and stumble over its weak points. In this article, I will pass along the magic of the commas — the not-so-secret tips and tricks that will take your essays from good to great in the snap of a proud English teacher’s fingers.

When Do You Use Commas?

When to use (and not use) a comma can be tricky if you aren’t familiar with the rules. You may use them sparingly for fear of misuse or pepper your paragraphs with unnecessary commas to break them up. Either of these practices will weaken your essays, however. Let’s take a look at some of the situations in which your writing will need commas:

To Separate Ideas

The first and most common use of the comma is to separate two ideas within a sentence. That being said, a comma isn’t always the right move, so knowing when not to use it is just as important as knowing how to use it.

Use a comma when the subject of the two clauses is different, or when the subject is repeated in the second half of the sentence.

• Example 1: I went to the store, and James went to the restaurant.
• Example 2: I went to the store, and then I went to the restaurant.

Do NOT use a comma when the subject has neither been changed or repeated.

• Example: I went to the store and bought a scarf.

Do NOT use a comma to separate two complete thoughts that are NOT joined by a conjunction. In this scenario, use a semicolon or simply break it into two sentences.

• I went to the store; James went to the restaurant.
• I went to the store. James went to the restaurant.

When Listing Items or Phrases

Commas are also used when listing items within a sentence. For example, you might want to list the things you want for Christmas, your favorite songs, the things about your little sister that you love the most, or your resolutions for the new year. (See what I did there?)

Use a comma when you are listing three or more items.

• Example: I want Santa to bring me a baby doll, a new bicycle, and a Red Ryder BB gun.

Pro tip: I always use the Oxford comma, which refers to the comma in between the next-to-last item in the list and the “and” or “or” that comes before the last item. Some people do not think the Oxford comma is necessary, and I think those people are wrong.

Do NOT use a comma if the items in your list are long phrases that use commas themselves. In this scenario, use a semicolon to more clearly differentiate between the list items.

• Example: I want a doll, whom I will name Sally; a new red bicycle, with support wheels included; and an official Red Ryder, carbine action, 200-shot, range model air rifle, with a compass in the stock and this thing that tells time.

To Separate Words or Phrases

One of the trickiest uses of commas is when separating specific words or phrases from the rest of the sentence. The rules here can get complicated and tough to remember, so, when in doubt, read the sentence aloud and see if you naturally pause at a particular point. If you do, chances are a comma belongs there.

Use a comma to separate introductory phrases, including direct addresses.

• Example: For the first time in forever, I’ll be dancing through the night.
• Example: Elsa, do you want to build a snowman?

Use a comma to separate nonessential phrases and appositives from the rest of the sentence.

• Example: I lost my notebook, which has the wifi password written on it, while crossing the Seine.

• Example: My best friend, a no-nonsense teacher from Arkansas, joined me for dinner.

Pro tip: When I refer to a “nonessential” phrase, that just means that the phrase could be removed from the sentence and it would still make grammatical sense. It does not mean the phrase is not important to the meaning or implications of the sentence. 

To Separate a Quote

The final most common use of commas is to separate a direct quote from the sentence around it. You may not use direct quotes very often in your college essays, but when you do, it’s important to get it right!

Use a comma before and/or after a direct quote.

• The fox said, “What are you doing in my foxhole?”

• The squirrel replied, “I was just taking a short nap,” and skedaddled out the back door.

Pro tip: When using a comma at the end of a quote, make sure to put it inside the quotation marks.

Do NOT use a comma at the end of the quote if it is a question or an exclamation. In those scenarios, use a question mark or exclamation point instead.

• Example: The fox asked his sister, “Why do you keep letting squirrels nap in our foxhole?” and shook his fist in the air.
• Example: The fox’s sister exclaimed, “You were so rude to my friend the squirrel!” and stomped out of the room.

And there you have it! The secret to great writing: the humble yet powerful comma. If you want to improve your use of punctuation, I recommend bookmarking this article and using it to double check your work until you have mastered the rules we covered. Computer programs like Grammarly can also provide you with instant feedback that help you build your grammatical muscles.

IvyWise is here to help you with all parts of your application — from commas to college lists. We’re your one stop for comprehensive support through every part of the admissions process — including confirming there are no commas out of place! Contact us today to see how we can help.