Most students, from middle school through college, have run across the abbreviations “i.e.” and “e.g.” in the course of their academic career. It’s common to assume that those two-letter abbreviations are similar to “ex,” which is often used as an abbreviation for “example.” But this isn’t quite correct, and can cause some confusion or even misunderstanding in the message we’re trying to convey. So what’s the deal with “e.g.” and “i.e.” — and when, if ever, do we need to use them?
They’re Abbreviations of Latin Phrases
Trying to puzzle out what “e.g.” and “i.e.” could stand for isn’t easy — at least not in English. They’re actually derived from Latin phrases: Exempli gratia is Latin for “for example” or “for instance,” while id est is Latin for “that is to say” or “in other words.”
The earliest English usage of the Latin phrase exempli gratia dates to the late 16th century, and there is evidence that id est was used in Old English before 950 CE. The English usage of both abbreviations dates to the early and mid-17th century.
They Aren’t Interchangeable
Despite their shared Latin origins, “e.g.” and “i.e.” should not be used interchangeably. It can be tricky to remember which one to use, but as a memory aid, remind yourself that “e.g.” means “for example” by remembering “‘e’ is for ‘example’” or “examples: good.” To recall that “i.e.” means “in other words,” remember that “‘i’ is for ‘in other words’ or ‘in essence.’”
Another way to remember the difference between “e.g.” and “i.e.” is to recall that “e.g.” expands a statement by giving examples, while “i.e.” clarifies a statement with a more specific description.
Example:
“He has many talents and interests, e.g., playing guitar, vegetable gardening, and studying French history.”
“He has many talents and interests, i.e., he’s a Renaissance man.”
Do I Need to Use i.e. and e.g.?
The short answer is: probably not, at least not in casual emails, or even in most professional settings. However, these Latin abbreviations tend to appear in academic and legal documents, so it’s a good idea to know what they mean and how to use them.
When writing “e.g.” and “i.e.,” the abbreviations should be lowercase, unless used as the first word in a sentence, and each letter should be followed by a period. And while many style guides require that foreign language words be italicized, such as exempli gratia and id est, there is no need to italicize “e.g.” and “i.e.” when they are in their abbreviated form. There’s also no need to add an additional period if either abbreviation comes at the end of a sentence. For example: “I couldn’t remember whether to use ‘e.g.’ or ‘i.e.’” However, if the abbreviation is in the middle of the sentence, a comma should be used after the abbreviation.
Can I Use “Ex” Instead of “e.g.”?
“Ex” is sometimes used as an abbreviation for “example” — perhaps if the writer couldn’t remember whether to use “e.g.” or “i.e.” or was concerned their audience wouldn’t know what “e.g.” meant. However, “ex” can also be used as an abbreviation for other words, including “exchange,” “executive,” “exercise,” “express,” “extinct,” and “extra,” and “Ex” is the abbreviation for a book in the Bible, Exodus.
For the sake of clarity, consider spelling out “example,” or using “e.g.” instead.
Featured image credit: PeopleImages/ iStock