On Parentheses () and Brackets [ ]

Updated September 8, 2022: Let’s discuss parentheses vs. brackets. Recently a reader had a question about brackets. Mutimba asked, “Where does the full stop go–behind the brackets or inside?” For brackets, he provided this visual: ( ).

I was grateful that he included a graphic, since in the United States, where a full stop is a period, Mutimba’s brackets are called parentheses.

As someone who writes in the U.S., I want to be clear about what I mean:

These are parentheses: ( ). In other countries they may be called brackets.

These are brackets: [ ]. In other countries they may be called square brackets.

Parentheses and brackets both serve to set off extra information without breaking the flow of the sentence or paragraph. Parentheses are much more common than brackets.


Her brother lives in Denmark but works in Germany (Hamburg).

She was born in Burma (officially known as Myanmar) and moved to England in 1995.

Grand prizewinners (from left to right) were Jared Hunter, Joan Hu, Kristi Thompson, and Ananth Vora.

Annual rainfall has increased (see Appendix B), and average temperatures have also increased.

Annual rainfall has increased (for details, see Appendix B).

Costs have increased 17 percent over the past five years. (See Table 2 on page 13.)

Further reading: The Place For Parenthesis

Mutimba asked where the period (full stop) belongs. The period follows the closing parenthesis except when the entire sentence falls within parentheses as a separate sentence. (This sentence is an example, as is the sentence directly above this paragraph.)

Further reading: Does Punctuation Go Inside Parentheses?

Brackets are much less common than parentheses. Use them to add information to quoted material, like this:

Mr. Moreau stated, “I graduated from Notre Dame [in South Bend, Indiana], but I am not a Catholic.”

In his email, he wrote, “There is never a restocking charge [emphasis mine], and we accept returns without question.”

Write something like this: “I reduced spending by 20 percent [or give actual dollars] in one year.”

Occasionally you may want to set off information that is already within parentheses. That is where brackets work. Examples:

(Attendees were Joan, Adriane, Carol [for the second half of the meeting], and Luis.)

(Additional information is available in a 23-page summary [link below] of the HIPPA Privacy Rule.)

(Possible dates are April 5, May 3, June 2 [a Saturday], and June 14.)

Have I answered your questions about parentheses and brackets? If not, let me know.

Syntax Training

Further reading: The Place For Parenthesis

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By Lynn Gaertner-Johnston

Lynn Gaertner-Johnston has helped thousands of employees and managers improve their business writing skills and confidence through her company, Syntax Training. In her corporate training career of more than 20 years, she has worked with executives, engineers, scientists, sales staff, and many other professionals, helping them get their messages across with clarity and tact.

A gifted teacher, Lynn has led writing classes at more than 100 companies and organizations such as MasterCard, Microsoft, Boeing, Nintendo, REI, AARP, Ledcor, and Kaiser Permanente. Near her home in Seattle, Washington, she has taught managerial communications in the MBA programs of the University of Washington and UW Bothell. She has created a communications course, Business Writing That Builds Relationships, and provides the curriculum at no cost to college instructors.

A recognized expert in business writing etiquette, Lynn has been quoted in "The Wall Street Journal," "The Atlantic," "Vanity Fair," and other media.

Lynn sharpened her business writing skills at the University of Notre Dame, where she earned a master's degree in communication, and at Bradley University, with a bachelor's degree in English.

12 comments on “On Parentheses () and Brackets [ ]”

  • Don’t forget that brackets can also be used if you’re making a minor change to a quote for clarification or style. A couple of examples:

    The superintendent stated, “I strongly agree with [the City Council] that a change is needed.” (In this case, the superintendent might have actually said “them,” but the quote, for whatever reason, requires more context.)

    The superintendent reassured the City Council that he “strongly agree[s]” a change is needed. (Here, the superintendent actually said “strongly agree,” but the “s” is needed for the sentence to be grammatically correct.

    Of course, brackets should be used sparingly in those types of cases.

    My biggest pet peeve lately has been the new fashion of using curly brackets { } in place of parentheses. I’m seeing it all over the blog world, and it makes me want to tear my hair out!

  • Hi, Nina. Thank you for adding your excellent examples.

    Curly brackets? I have not been seeing them, but maybe I have selective vision.

    I worry for your hair!


  • Hi, Val. Interesting question! I do not remember having seen two sets of parentheses the way you show them.

    I am not certain the semicolon will communicate to your readers the correct relationship between the ideas.

    Why not set off one of the parenthetical comments with commas or dashes? When I was creating examples for this blog post, I rejected several of my sentences because they were too cumbersome with parentheses or brackets. Other punctuation–namely, commas and dashes–seemed more efficient.

    I will continue to think about your question.


  • Do you know what the standard policy is for putting two sets of parentheses next to each other? For example, “The existing design analysis (where variable from previous calculations) (conditions at Location 5)…”

    Would it be better to put the phrases in one set of parentheses with a semicolon in between? I can’t decide which way looks best.

  • Lynn, I think you’re right that I need to change the punctuation in the example sentence. But sometimes we have two items that would normally be in parentheses in our style, such as acronyms and figure references. I find it odd when people write, “The site can be found on the local Flood Insurance Rate Map (FIRM) (see Figure 2).” I change it to, “The site can be found on the local Flood Insurance Rate Map (FIRM; see Figure 2). I haven’t found this issue in the grammar books I have, so I just wondered what you would do.

    Thanks – I really do value your experience and objective opinion!

  • Hi, Val. Thank you for offering another example. Now I understand what you mean. I agree with your desire to avoid (__) (__).

    If I were editing your example, I believe I would choose not to use the acronym in the sentence. I might use it the next time “Flood Insurance Rate Map” appears, or I might use it with the spelled out name in the caption for Figure 2.

    Another alternative is to restructure the sentence to avoid the double parentheses:

    The site can be found in Figure 2, the local Flood Insurance Rate Map (FIRM).

    What do you think of these ideas? Thanks for asking.


  • Hello Ms Lynn,
    i’am from Algeria,i’ve studied Law i speak Arabic and French but i need english also in my work.that’s why i visit your web site everyday.
    Thank you my teacher.

  • Thank you for your thoughtful message, Ilyas. I am pleased that you visit this site.

    When you write in English, remember to capitalize “I” when it refers to the speaker. Example: “I am from Algeria.”

    I wish you success with English.


  • I know this is an old topic, but I still have a question about double parentheses. What if you can’t rearrange the sentence to avoid it? For example “The method was developed by Smith et. al. (2008)(Table 1).”

    Would it be better to write “The method was developed by Smith et. al. (2008; Table 1).”

  • Hi, Jill. According to “The Chicago Manual of Style,” both back-to-back parentheses and the semicolon approach are acceptable. “Chicago” states:

    “Parentheses may appear back to back (with a space in between) if they enclose entirely unrelated material; sometimes, however, such material can be enclosed in a single set of parentheses, usually separated by a semicolon.”

    Your comment came while I was away on vacation. I apologize for the delay.


  • I just looked in APA 7th edition book and it says:

    back to back [parentheses]
    Correct: (e.g., defensive pessimism; Norem & Cantor, 1986)
    Incorrect: (e.g., defensive pessimism) (Norem & Cantor, 1986).

    pg. 94

  • Hi, Jessica. Your example agrees with “The Chicago Manual of Style.”

    The phrase “defensive pessimism” comes from Norem and Cantor, so their names should not be in a separate set of parentheses.

    Thanks for the example.


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