Square Brackets [ ]
Summary
Use square brackets to enclose text added to a quote by someone other than the original speaker or writer. This could be an editorial correction, clarification, or other explanation.
- He insisted that “it [the decision] was fair.”
- She describes making peace with her past. “Good and bad [memories] make us who we are.”
Place the Latin word sic (traditionally italicized) within brackets to indicate that quoted text has been reproduced exactly, including any errors or unexpected turns of phrase.
An occasional feature, ‘The Den of Villany [sic],’ was a forum for Douglass to comment on discrimination in American society.
— “The North Star (American Newspaper),” Encyclopedia Britannica (Accessed September 8, 2022)
Enclose in brackets any parenthetical material that appears in text already within parentheses.
- This disrupts communication and navigations patterns of marine animals (including dolphins and whales [Table 1]), causing a decline in local populations.
- The adverb sic is italicized and placed in square brackets. (Parentheses [round brackets] are used instead in some styles.)
![Graphic titled "Square Brackets." The left panel shows an illustration of two people pushing together a pair of square brackets that enclose the title against a yellow background of lots of tiny brackets. The right panel explains when to use them and provides examples. Use 1: To enclose text added later to a quoted passage. Example: "This new source [of energy] will change how humans live in the twenty-first century." Use 2: To add an editorial comment or clarification. Examples: "They [the two nations] wish for peace." "As Dash notes, "Peace /requires/ freedom" [italics mine]. Use 3: For brackets within parentheses. Examples: Pollution affect pollinators (insects and birds that pollinate flowers [e.g., bees]). They have launched a new initiative (the Clean Energy Action Plan [CEAP]).](https://editorsmanual.com/wp-content/uploads/2022/09/square-brackets-media-1024x576.webp)
Square brackets: When are they used?
Square brackets (or simply brackets) are punctuation marks used mainly to enclose additional text that is not originally part of the surrounding passage. This is information added later by someone other than the original speaker or writer—an explanation, editorial clarification, correction, or translation. Square brackets are also used when brackets are needed within parentheses.
- He continued, “It [the vaccine] has been clinically tested, and we [health officials] are confident it will save lives.”
- “The two cities [Nusquam and Pouthena] will now be on the map.”
- “Patients can now [have their eyes checked] while they wait.”
- She believes that people should not attempt to “logicize [sic] religion.”
- They reviewed safety features of boats, canoes, and rafts (as part of the overall investigation into portable floating devices [PFDs]) for this report.
- Some cats prefer laser to feather toys (see The Complete Guide to Cats [1991]).
In this article, we discuss when to use square brackets and how to use them correctly.
Comments and clarifications in quoted text
When you quote someone, enclose in square brackets any comments, clarifications, interpolations, explanations, and other information added later and not in the original speech or text.
- “Various therapies can help patients better manage MS [multiple sclerosis].”
- He claims that he has “found the ultimate cure [for sleep disorders], which is to live alone in a cave for three months.”
- “She [the CEO] will not be appearing in court.”
- Dark matter, according to Dash, explains the expansion of the universe. [Other physicists suggest modifying the theory of general relativity.—Ed.]
- “It took all her resolution not to cry when she bade farewell to [her cat] Mike, who was curled up on the sun-warm grass at the back door” (Lucy Maud Montgomery, Emily of New Moon, 1923).
Such editorial interpolations can help clarify an unclear pronoun reference in quoted text.
- “She [the governor] will deliver an address to the Legislature later today on the matter.”
- “They [the students] were exploring the canyon without adult supervision.”
- Dash clarifies her earlier statement: “We [editors] have a duty to not change the intended meaning of a text.”
You may also simply replace an unclear pronoun. Enclose the replacement in square brackets to indicate it has been changed from the original.
-
“[The governor] will deliver an address to the Legislature later today on the matter.”
A replacement rather than an additional insertion can make for smoother reading, particularly in news copy and other writing meant for a general audience. Also enclose in square brackets a word inserted in quoted speech that was not in the original.
- “I mean such [solutions are] only temporary. What we need is a long-term cure.”
- “We have asked [the mayor] for clarification.”
If quoted text already contains brackets, write “brackets in the original” in the source reference to clarify that this is not an addition to the original text.
- It is important that she [the president] remain neutral (Minerva Dash, October 1999; brackets in the original).
In a translation, square brackets may be used to enclose a term in the original language if you think this would be useful to readers.
- Sartre distinguishes between being in-itself [en-soi] and being for-itself [pour-soi].
Square brackets can also enclose any other information you think may be useful to the reader, like a translation or phonetic transcription, which you add later and is not in the original text.
- Dash explains, “The Japanese concept of Kaizen [improvement] became popular in the West in the nineties.”
- “The plural of base is bases [beɪsɪz] and that of basis is also bases [beɪsiːz], pronounced differently.”
To indicate emphasis
If you emphasize a portion of quoted text (e.g., by italicizing it), inform your readers of this change by inserting a clarification in square brackets. Write “emphasis mine,” “my italics,” “italics added,” or something similar.
- As Russell says, “It is clear that the most elementary condition, if thought is to be free, is the absence of legal penalties for the expression of opinions” [emphasis mine].
- Davis (1989) disagrees: “The process of empowerment cannot be simplistically defined in accordance with our own particular class interests” [italics added].
If the emphasis in a passage is from the original text (not added by you), this may be specified by inserting in square brackets a clarification that says “emphasis in the original text,” “italics in original,” or similar. Do so only if you consider it necessary to clarify this, perhaps because other portions of the text have been changed. (If no clarification is provided, emphasis is automatically assumed to be in the original text.)
- “[Syndicalism] is concerned with reforming actual work, and the organization of industry, not MERELY with securing greater rewards for work” (Bertrand Russell, 1918; emphasis in the original text).
The pronoun “it” in the original has been replaced by the word “syndicalism” in the quoted text, indicated by means of square brackets. But emphasis on the word “merely” was in the original text by Russell. The author clarifies this to the reader in the source citation, where square brackets are not required.
- As Woolf’s Mrs. Hilbery says, “There are some books that live” [italics in original].
The square brackets indicate editorial clarification.
To adjust sentence structure
It may be necessary to adjust the grammatical structure of quoted text to match the passage in which it appears. This could be a change in tense or verb form. When you make such a change, enclose the altered text in square brackets.
- Original: “I hate grammar.”
Quoted: My English teacher said she “hate[s] grammar,” which is not confusing at all. - Original: “We have asked for clarification but haven’t received any.”
Quoted: The researchers stated that they “[had] asked for clarification but [had not] received any.”
With sic
The Latin sic is used to indicate that a quotation has been exactly reproduced, including any spelling or grammatical errors in the original text. Sic comes from Latin and literally means “so,” loosely translated as “intentionally so written.” It signifies an intended reproduction of original text, errors and all. The term sic is traditionally italicized and enclosed in square brackets in formal writing.
- In a tweet, the then president-elect called it an “unpresidented [sic] act.”
- Poco wrote back to say, “The chip [sic] has sailed,” which, despite her earlier tears, was a bit of a relief.
- The Governor said she “could [sic] care less” about gun violence.
Using sic isn’t always necessary. Pointing out someone’s grammatical errors can seem needlessly judgmental, and silent editing is becoming increasing acceptable. You may simply correct a spelling mistake or grammatical error, or if necessary, replace the typo with the correct word in square brackets. Sic is necessary only if you must print quoted words exactly.
Sic need not always indicate a grammatical error. It can simply signify an uncommon spelling, an unexpected turn of phrase, or an opinion that is unacceptable or unpopular—that someone has been quoted verbatim.
- His latest venture is titled “Carzzz” [sic].
- He remained committed, he said, adding, “Wild lions [sic] couldn’t drag me away.”
Inside parentheses
Use square brackets to enclose parenthetical material that appears in text already in parentheses (brackets within brackets).
- Pollution affects pollinators (insects and birds that pollinate flowers [e.g., bees and butterflies]).
- In her debut novel (On Silence [1982]), Dash creates a world so unreal in its reality that it blurs the lines between truth and disbelief.
- Sea levels rose to their highest in a century (based on data collected across 14 locations [Table 1]).
- Many cats enjoy being brushed (see The Complete Cat Manual [pp. 373–4]).
Don’t use square brackets if the text inside parentheses can be set off using commas instead. Commas are less intrusive than brackets.
- Poor: Pollution affects pollinators (insects that pollinate flowers [like bees and butterflies]).
Better: Pollution affects pollinators (insects that pollinate flowers, like bees and butterflies).
In citations
Many citation styles call for the use of square brackets (e.g., to cite an author’s pseudonym, to provide an abbreviation, or with in-text citations). Here are some examples.
- MLA (Works Cited): Asimov, Isaac [Paul French]. The Complete Adventures of Lucky Starr. Doubleday, 1952.
- APA (Reference List): Bureau of Labor Statistics. (2022). Consumer expenditures, 2021 [Annual report]. https://www.bls.gov/opub/reports/consumer-expenditures/2020/home.htm
- APA (in-text): Cats like pizza (Association of Cat Lovers [ACL], 1999).
- IEEE (in-text): Cats like pizza, as experimentally shown by Dash [1], [2].
- Chicago (in-text): Cats prefer pasta (Femy R. [New York], June 3, 2021, reply to Dash 2021).
Square brackets with other punctuation
Other punctuation marks like periods and question marks are used the same way with square brackets as they are with parentheses (round brackets). Punctuation goes inside brackets if it belongs to the bracketed material but outside if it is part of the surrounding text.
- As postulated by Dash (The Complete Guide to Cats [1991?]), cats are adept at interdimensional travel.
- Cats, according to Dash, can travel through time. [Other researchers believe teleportation to be a more likely explanation for feline kinetics.—Ed.]
- Feline interdimensional travel was first investigated by Minerva Dash (The More Complete Guide to Cats [1993]).
- Feline interdimensional travel was first investigated by Minerva Dash in 1993. (Further research was then conducted by Femy [1995].)
Brackets vs. parentheses
Parentheses and brackets both enclose additional information. Parentheses are used mainly to set off explanatory material from surrounding text, whereas brackets enclose information added to quoted text by someone other than the original writer.
- Parentheses for explanatory information: We need emergency supplies (blankets, medicines, food, water, etc.).
- Brackets for insertion in quoted text: “These [supplies] are needed to keep people warm through the night.”
Brackets can also enclose parenthetical material, but only if it appears within text already enclosed in parentheses.
- Brackets within parentheses: They have asked for help (including emergency supplies [blankets, medicines, food, and water]).
Round brackets are called parentheses in U.S. English, with square brackets being referred to as brackets. In British English, the word brackets refers to round brackets, and square brackets are known as such.
Examples from published content
Here are some examples from published content that illustrate the use of square brackets.
- To insert an editorial clarification
‘I think the biggest thing they [super-deep diamonds] inform us about is the process of subduction,’ says Smith.
— Zaria Gorvett, “The ‘Super-Deep’ Royal Diamonds Revealing Earth’s Secrets,” BBC Future (September 23, 2022) He describes people who have come to reassess their basic values, so that they change jobs, travel the world or commit themselves to charity work. ‘They’ve channelled [their distress] into something positive.’
— The Complicated Truth of Post-Traumatic Growth, BBC Worklife (March 14., 2022)Pentagon spokesman Peter Cook later said in a statement: ‘Through direct engagement with Chinese authorities, we have secured an understanding that the Chinese will return the UUV [unmanned underwater vehicle] to the United States.’
— “Donald Trump Accuses China of ‘Unpresidented’ Act over US Navy Drone,” Guardian (December 18, 2016)- To insert a comment in quoted text
‘I knocked at your door but had no answer so gather you’ve taken my advice and are sleeping off last night. . . . Don’t think any more about the dress. [This last was heavily underlined] Yours affectionately, Bee. [And a postscript] You must both come over and see us soon.’
— Daphne du Maurier, Rebecca (1938) - Sic to indicate an exact reproduction, including errors
‘Blue . . . signifies vigilence [sic], perseverence [sic] & justice.
— “Flag of the United States of America,” Encyclopedia Britannica (Accessed September 8, 2022) - In a citation
Upon her return to Amherst, Dickinson confined herself to the Homestead, declaring, ‘I do not cross my Father’s ground to any House or town’ (Letters 330 [L330], p. 460).’
— Paul Crumbley, Emily Dickinson’s Life (2000) - To quietly correct grammar or spelling
The making of the gooseberry jam and a good recipe for orange wine interests her more than all the marchings and countermarchings, the man[oe]uvres and diplomacies, going on the world over.
— Jane Austen, The Letters of Jane Austen (Edited by Sarah Chauncy Woolsey) (1908) - Brackets within parentheses
The most predictive neural activity was associated with reward processing (ventral striatum [VS]) and the ability to simulate the minds of others (temporoparietal junction [TPJ] and dorsomedial prefrontal cortex [DMPFC]).
— Scott Barry Kaufman, “The Neuroscience of Social Influence,” Scientific American (July 9, 2013)
Usage guide
The primary use of square brackets in English is to enclose an editorial comment, correction, or clarification, or any other change made to quoted text by someone other than the original speaker or writer. Brackets are also used in source citations. Brackets are not interchangeable with parentheses but can enclose parenthetical material that appears in text already within parentheses. Finally, any punctuation goes inside square brackets if it belongs to the bracketed material but outside if it belongs to the larger sentence.