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.
Examples:
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.
Lynn
Syntax Training
Further reading: The Place For Parenthesis