Grammar Check: I.e. vs. E.g.

When should you use i.e., and when should you use e.g.?

I.e. and e.g. are not interchangeable. They are abbreviations of different Latin phrases and have different meanings.

I.E.

I.e. is an abbreviation of the Latin phrase id est. Its translation into English is “it is.”

Do not use i.e. to indicate an example of something, but rather the actual thing. It refers to a precise item, or items, and is used  to clarify or specify. Think of it as a replacement for “in other words” or “that is.”

Example:

Factors beyond Bob’s control—i.e., severe weather conditions and impassable roads—made it impossible for him to go to work.

We know from the above sentence that the only factors that prevented Bob from going to work were weather and road conditions.

E.G.

E.g. is an abbreviation of the Latin phrase is exempli gratia. Its literal translation into English is “for the sake of an example.”

Use e.g. to indicate an example of something. It refers to one or more examples but, unlike i.e., some of the examples are omitted. Think of it as a replacement for “for example.”

Example:

Bob has many chores to do (e.g., home repairs, cleaning, and snow shoveling).

We know from the above sentence that Bob has more chores than those mentioned in the list.

Other things to keep in mind

There is a period after each of the letters. The reason: Each letter is an abbreviation of a longer word.

Both e.g. and i.e. are followed by commas.

Both e.g. and i.e. are lowercase when they appear in the middle of a sentence. When starting a sentence with one or the other, capitalize the first letter but not the second. 

Do not add etc. to the end of a list that begins with e.g. It is self-evident that there are more examples.

Do not italicize either e.g. or i.e. (They are italicized in this article because I am explaining them, not using them. Note that in my examples about Bob they are not italicized.)

Once again, in British English there are slight differences. The periods and commas may be omitted.