Brackets vs. Parentheses: How to Use Them

Though these symbols—( ), [ ], { }, and ? ?—regularly appear in our books and screens, they all have odd, unexpected origins. Let’s explore them a bit closer and find out their actual names, too!

What are brackets?

If you’ve ever seen these keys on your computer: { }, [ ], or < >, well then you know where all of the types of brackets are, good job!

The word bracket is related to the French braguette from the name for codpiece armor, which is literally the piece around the … uh, man cod that bears resemblance to the architectural features of the bracket, among other things. According to Etymonline, “The typographical bracket (‘marks used to enclose a note, reference, explanation, etc.,’ formerly called crotchets) is first recorded 1750, so called for its resemblance to double supports in carpentry (a sense attested from 1610s).” Around 1880, brackets also came to mean “a group bracketed together as of equal standing in some graded system.” So, this (bracketing with others) is probably where sports brackets came from then. Aha!

What are square brackets [ ]?

Square brackets ([ ]) are used inside of parentheses to denote something subordinate to the subordinate clause. Here’s an example from the 13th edition of the Chicago Manual of Style: “During a prolonged visit to Australia, Gleuk and an assistant (James Green, who was later to make his own study of a flightless bird [the kiwi] in New Zealand) spent several difficult months observing the survival behavior of cassowaries and emus.”

What are curly brackets { }?

These { } have a variety of names; they are called braces, curly brackets, or squiggly brackets. Usually these types of brackets are used for lists, but online, they also signify hugging in electronic communication.

What are angle brackets < > or ? ??

The last confusing symbol, ? ?, is called an angle bracket or the chevron. The word originally meant rafter in Old French and likely came from the Latin term caper, meaning “goat.” The symbol does somewhat resemble the hind legs of those animals, right? Today, it is most often used in complex math problems. Parentheses, brackets, and chevrons are also used in computer science and programming, too.

What are parentheses ( )?

The most familiar of these symbols is probably the ( ), called parentheses. Fun fact: one of them is called a parenthesis, and as a pair, the plural are parentheses. Parenthesis literally means “to put beside,” from the Greek roots par-, -en, and thesis. Outside of the US, these can be called round brackets.

The use of parentheses in printed English dates back to at least 1572.

Write smarter with our thesaurus-powered Grammar Coach™! Get spelling help, synonyms suggestions, grammar check and more! Sign up now!

Parentheses and brackets in writing

How to use parentheses in writing?

Grammatically, they behave kind of like commas and serve to set aside a part of the sentence or discussion. Parentheses can also be used as interrupters in sentences to create a more informal, casual style of writing.

Parentheses offset text that isn’t important to the meaning of a sentence. Things like extra information, clarifications, asides, or citations. The information inside the parentheses can be as short as a number or a word, or it can be as long as a few sentences. Parentheses always appear in pairs. They’re often used where commas would also be appropriate.

A sentence should be able to stand on its own without the parenthetical information. For example: “The little girl (and her baby doll) skipped across the park to her mother.”

In writing, parentheses can also be used to show a plural version of a singular word. For example: “The girl(s) fell into the hole.”

MLA format also uses parentheses for in-text citations.

For more about parentheses in writing and how to use punctuation with them, read our article that dives deep into parentheses.

How to use square brackets in writing?

Square brackets [ ] are used to enclose a section of writing or printing to separate it from the main text. They can be used like parentheses, but are often used less often in writing for that purpose.

One main use of square brackets in writing is in conjunction with the word sic. To learn more about quoting accurately with sic read our deeper dive into the term.

Another way square brackets tend to be used in writing is to insert a word or name for clarification (that is not in the original text). Just like sic above, it helps clarify what is written. For example: “She [Malia] told me it was wrong.”

How to use curly brackets in writing?

Curly brackets { } aren’t used much in writing, they’re seen more in math and programming (scroll down a bit to learn how).

But, when you do see them in writing here and there, the main ways they are used are to hold lists of items or to hold a term or terms that are equal to the one written.

Here are some examples:


  • Lists: These are all of my friends {Sam, Ilya, Malik, Bri}.
  • Equal terms: Use your preferred social media platform {Twitter, Instagram, Facebook, Tiktok}.

How to use angle brackets in writing?

In writing, angle brackets are rarely seen … in English that is. In other languages, angle brackets are used in doubles << >> and replace quotation marks.

When they are used in English writing, they can sometimes signal a data point, such as “The delivery happened at <<TIME>> on <<DATE>>.

You can also use double angle brackets to mark an action or set a status, such as <<Out to Lunch>>.

Parentheses and brackets in math

When it comes to parentheses and brackets in math equations, they are used to signify order, you know, like in order of operations.

The correct order to address equations in parentheses and brackets is as follows: first solve equations in parentheses ( ), then the square brackets [ ], and then the curly brackets { }.

Curly brackets { } can also be used in sets in math. Sets are just a grouping of numbers. An example is {1, 3, 5, 7, 9}.

How to use angle brackets in math?

Angle brackets typically are used as “less than” and “greater than” signs in math. Examples include: 8 < 16 or 20 > 1.

There are some specialized usages of angle brackets in complex mathematical fields like quantum mechanics as well … but we’ll let the experts explain those usages.

Parentheses and brackets in programming

Each type of bracket and parentheses has a specific function in programming, as well. Scroll to take a look what they are.

How to use parentheses in programming?

In programming, especially Javascript, parentheses are used to show that a word is a function.

An example is: showMyWordList (“Elementary Word List”).

How to use square brackets in programming?

Square brackets are used for arrays, specifically in Javascript.

An example is: var color = [“blue”, “teal”, “turquoise”].

How to use curly brackets in programming?

Curly brackets are used to show where a function starts and ends. Simple.

How to use angle brackets in programming?

 Angle brackets are used in a different way for programming: as “less than” and “greater than” signs. So that means they don’t contain any information at all when it comes to programming in this way; instead they represent if a value is less than or greater than another value in the code.


If you think these grammatical symbols are perplexing, wait until you meet the interrobang and other unusual and underused marks.