Want to brush up on your Latin before your trip to Latin America? Funny question, right? No one uses Latin anymore! But interestingly, we still use Latin expressions. For example, the abbreviations e.g. (exempli gratia) and i.e. (id est) are abbreviations for Latin terms that are often confused.
For example, a student writes the following sentence:
Mass transport is dictated by how quickly a substance (i.e., water) can
adsorb and desorb from the electron double layer (EDL) interface.
Because i.e. was used, the reader understands that water is the only substance the writer is referring to–not oil, or alcohol, or any other substance. If on the other hand, the writer wanted the reader to understand that a variety of substances, including water are possible, then he/she would choose e.g. Think of i.e. as meaning “in other words,” or “that is to say,” and e.g. as meaning “for example.”
Here are two more examples.
Critics (i.e., Prince William and Prince Harry) say that Camilla Parker
Bowles packs the stylistic punch of Yorkshire pudding.
This sentence indicates the specific critics are Prince William and Prince Harry.
Critics (e.g., Prince William and Prince Harry) say that Camilla Parker
Bowles packs the stylistic punch of Yorkshire pudding.
This sentence indicates two critics are Prince William and Prince Harry, but there are more critics. These are provided as examples of the pool of critics. (Aside: I think of the two sentences, this second one is more valid.)
Notice the use of a comma after i.e. and e.g. in the sentences. This is recommended by most style guides, including the Chicago Manual of Style.