e.g. or i.e.?
“Do not confuse these two abbreviations, which mean different things and have different origins. The abbreviation e.g., meaning “for or as an example,” comes from the Latin expression exempli gratia (“for example”). Use it when you want to list a few typical examples of the thing mentioned: I have the laboratory equipment, e.g., [not i.e.] beakers, thermometers, and test tubes, that we need. Do not end a list that starts with e.g. with etc. The abbreviation i.e., meaning “that is, that is to say,” comes from the Latin expression id est (“that is”). Use it when you want to give a more precise description of the thing mentioned: The hearing, i.e., [not e.g.] the preliminary hearing, is set for noon Friday. Two periods punctuate e.g. and i.e. in U.S. English, whereas they may be unpunctuated in British English. Surround these abbreviations with commas.” –Encarta
I have never actually known the correct use of these until now…damn the public school system.
For a more graphic example, I recommend The Oatmeal – always good for an “oooohhh….” and an embarassed chuckle as you think about your most recent grammar errors (i.e. grammors). Had to use an “i.e.” correctly somehow.