What Are Parentheses And How Do You Use Them?

Punctuation can get pretty tricky (especially those darn commas). However, punctuation can be mastered if you put in the effort. It won’t come easy (it never does), but mastering punctuation will help bring your grammar to the next level. If you are interested in beginning (or continuing) your dominance over punctuation marks, mastering parentheses will go a long way in making your punctuation perfect. Are you ready? (We are!)

What are parentheses?

Parentheses are a pair of punctuation marks that are most often used to add additional nonessential information or an aside to a sentence. Parentheses resemble two curved vertical lines: ( ). A single one of these punctuation marks is called a parenthesis. It is considered a grammar error to only use a single parenthesis; parentheses are always used in pairs in proper grammar.

When do you use parentheses?

Typically, parentheses are used sparingly in formal writing. In general, the most common usage of parentheses is to add asides or unessential additional information. However, there are several other reasons a writer may choose to use parentheses.

Additional information

Parentheses can be used within or after a sentence to give additional context. This information is almost always unessential, offers an aside, or states the writer’s commentary. Information inside parentheses can be a word, a sentence fragment, a complete sentence, or multiple complete sentences:

• Single word: He put ketchup and mayonnaise (yuck) on his hot dog.
• Sentence fragment: Champ is a loyal police dog (and a good boy).
• Sentence: Norlen, Norlen, and Cuddleswuffles (don’t ask) is the most prestigious law firm in the city.
• Multiple sentences: The city was saved by our friendly neighborhood Spider-Man. (Is he really a hero? I have my doubts.) 

When using parentheses, the information contained within them should be unessential. You can test this by removing the parenthetical information and seeing if the sentence is still clear and makes sense. If it doesn’t, consider rewriting your sentence without parentheses. For example,

• Unessential: Pumpkin pie (my favorite kind of pie) is delicious. Pumpkin pie is delicious.
• Essential: July (and June) are summer months. July are summer months.

Other uses

Although less common, there are a variety of other situations in which it is considered acceptable to use parentheses. These include:

References and sources: In research and academic writing, style guides typically advise using parentheses to direct a reader to charts, tables, illustrations, and other reference material. For example, a sentence might read Air pollution has increased by 100 percent. (See Chart 12.) Similarly, citations that direct a reader toward a source list or bibliography are often placed after a sentence inside parentheses. For example, an article might include a sentence that says According to leading scientists, cats consider humans to be nothing more than servants. (Tabby and Meowcolms, 2005)

Abbreviations and acronyms: Parentheses are used to explain the meaning of an unfamiliar abbreviation or acronym or to introduce an abbreviation or acronym that will be used in the rest of the writing:

• The case was handled by the DEA (Drug Enforcement Administration).
• Ghosthunting is handled by the Bureau of Odd Occurrences (BOO).

Area codes: When giving a phone number, the area code is typically contained within parentheses:

• Bailey can be reached at (555) 123-4567.

Lifespans: When relevant, a historical person’s birth and death date are included in parentheses:

• Albert Einstein (1879–1955) was one of the greatest scientific minds of recent history.

Numbered or lettered lists: Lists that are separated by numbers or letters may use parentheses to make something easier to read:

• You need to bring three things to the camping trip: (1) a tent, (2) a sleeping bag, and (3) plenty of extra food.
• Any formal request for adding pineapple to the pizza must include: (a) your name, (b) your age, (c) your address, and (d) a trash can to throw the request into.

How are braces (or curly brackets) used for lists? Find out here.

How to use parentheses

There are a few things to know when using parentheses to add asides or additional information.

It is improper to use one parenthesis

To properly use parentheses, include all of the additional information between a pair of parentheses. For example,

❌ Incorrect: Halloween my favorite holiday) is right around the corner.
✅ Correct: Halloween (my favorite holiday) is right around the corner.

Punctuation

When it comes to punctuation, style guides may differ on the specifics of using parentheses. In general, the punctuation mark that the sentence uses comes after the parentheses:

• The witch was mean to Dorothy (and her friends).

If the parentheses includes a question or exclamation, it is okay to put a question mark or exclamation point inside the parentheses:

• I like candy (Who doesn’t?), but you can’t eat it all of the time.
• I have a party today (Yay!) and a dentist appointment tomorrow (Boo!).

When used in sentences, parentheses typically come before a comma and not after:

• Typical: She gave me a gift (the coat I wanted), and I gave one to her.
• Atypical: She gave me a gift, (the coat I wanted) and I gave one to her

Capitalization

Like punctuation, the rules of capitalization when using parentheses often depend on the style guide or grammar resource that you use. In general, the first word inside parentheses is typically capitalized if it is a proper noun or it begins a new complete sentence.

• That girl (Jessica, I think) was really nice to me.
• I really like geese. (Swans are a whole different story.)

When parentheses are used in the middle of a sentence, most grammar resources typically only suggest to capitalize the first word of a complete sentence if it is a question or exclamation:

• Capitalized: She said she saw Pete (Who?) by the bus stop.
• Capitalized: We were beginning our seventh hour of the Lord of the Rings trilogy (They are long movies!) when the power went out.
• Usually not capitalized: We bought all of the pink balloons (they were out of red ones) for the birthday party.

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