These two little Latin abbreviations get abused more than any others that I encounter in text. I suspect it has something to do with the fact that they both contain two letters and two periods and have similar uses. Their misuse is unfortunate because they do, in fact, have totally different identities:
e.g. = exempli gratia (for example)
i.e. = id est (that is)
We use e.g. to present examples and i.e. to rephrase for clarity.
Sample sentence:* Latin abbreviations are generally set in roman type (i.e., they are not italicized or bolded), although Latin words are sometimes italicized in English text (e.g., et alia).
Rules of use
1. Only use e.g. and i.e. in parentheses. When using them in text, write them out as "for example" and "that is," respectively. Following this rule, we can rewrite the above sample sentence like this:
Latin abbreviations are generally set in roman type — that is, they are not italicized or bolded — although Latin words are sometimes italicized in English text; for example, et alia would be et alia.
2. Always use a comma after either of them: e.g., & i.e., Don't use a colon or semicolon.
*The sample sentence was taken from Editing Canadian English, 2nd Edition.
Want more quick and painless writing tips? Leave a comment letting me know which ones you want me to cover!