The abbreviations i.e. and e.g. can streamline examples and specific information in your sentences; however, they aren’t interchangeable, and their placement within parentheses depends upon the type of content you’re writing. Here is a quick look at how they differ and how to use them.
Understanding the Difference between i.e. and e.g.
The abbreviation i.e. stands for id est, which is a Latin term that means “that is.” Use i.e. when you’re identifying all of the information referenced in the sentence.
Emmylou needs to buy the rest of her school supplies (i.e., three notebooks, two mechanical pencils, and a calculator) before summer semester begins next week.
Nelson stopped at Trader Joe’s for his favorite foods (i.e., orange chicken, speculoos cookie butter, and crystallized candied ginger).
The abbreviation e.g. stands for exempli gratia, which is a Latin term that means “for example.” Use e.g. when you’re providing an example of the information referenced in the sentence but not all of the information.
Pancho enjoys playing with his cat toys (e.g., mice, crinkle balls, and laser pointers) after his third afternoon nap.
Lefty likes to snack on his human’s food (e.g., toast, chicken nuggets, and tater tots) more than his cat treats.
Using i.e. and e.g. in Business, Scholarly, and Journalistic Writing
In business and scholarly writing, i.e. and e.g. normally appear in parentheses within the body content, as shown in the examples above. They may appear outside of parentheses in footnotes and endnotes.1 However, i.e. and e.g. sometimes appear without parentheses in newspapers and magazines.2
Whether you’re writing business, scholarly, or journalistic content, use periods between the letters and use a comma after the second period—unless you’re following British English, which commonly omits the comma after i.e. and sometimes omits the periods in e.g.3
1. Publication Manual of the American Psychological Association, 6th ed. (Washington, DC: American Psychological Association, 2010), 108; The Chicago Manual of Style, 17th ed. (Chicago: University of Chicago Press, 2017), 5.250, 6.51.
2. The Associated Press Stylebook 2018 (New York: Associated Press, 2018), 96, 144.
3. Bryan A. Garner, Garner’s Modern English Usage (New York: Oxford University Press, 2016), 480.