What do you do when you need to insert a set of parentheses within another set of parentheses?
This is an issue that commonly arises in academic writing, particularly when inserting additional information about an in-text reference. For example, you have a parenthetical element, such as an in-text reference (e.g. Elite Editing, 2023). Now, you want to add an additional parenthetical element, such as an abbreviation (EE), into the parentheses. Keeping them as they are (identically curved), can lead to confusion about where the elements start and stop. This is called ‘nested parentheses’.
One solution is to turn the interior parentheses into square brackets [ ], to distinguish them from the original curved parentheses ( ). For example:
- (e.g., Elite Editing [EE], 2023)
- (some critics, such as Dubosarsky , have used parentheses many times)*
- (I would [usually] not recommend constructing a bullet list consisting [entirely] of parenthetical elements).
* However, please note that if you are using APA referencing style, you would use commas around the date instead of square brackets: (some critics, such as Dubosarsky, 2014, have used parentheses many times)
Another solution is to use a combination of parentheses and em rules. For example, instead of:
Dr Jones (an authority on the issue under review (smoking cessation strategies)) discussed this at length in his paper.
Dr Jones—an authority on the issue under review (smoking cessation strategies)—discussed this at length in his paper.
Yet another solution is to reword the sentence. For example:
Dr Jones is an authority on the issue under review (smoking cessation strategies), and he discussed this at length in his paper.
What’s the difference between a square bracket and a parenthesis?
The terms ‘bracket’ and ‘parenthesis’ are often used interchangeably to describe either ( ) or [ ]. However, the Oxford Dictionaries (Oxford University Press, 2014) state that these ( ) are ‘parentheses’, and these [ ] are ‘brackets’. This terminology is also commonly used in mathematics.
American Psychological Association (2020) Publication manual of the American Psychological Association, 7th edn, American Psychological Association , Washington, DC.
APSC (Australian Public Service Commission) (2021) Australian Government Style Manual, stylemanual.gov.au.
Updated 5 October 2023
Ellen McRae, PhD, AE (IPEd), MNZSTI
Senior Managing Editor