What's the correct punctuation of "i.e." and "e.g."? [duplicate]

Solution 1:

The distinction probably emerges from their different meanings in Latin, which grants them different usages in writing.

E.g. (exempli gratia in Latin, meaning “for example”) should be generally followed by a list of examples. Thus, adhering to proper English style usually requires commas to follow e.g. to delimit the beginning of that list.

I.e. (id est in Latin, meaning “that is”) is used to recapture the meaning of an antecedent clause by rephrasing. Typically, it is only followed by a clause describing a singular entity, and so does not require a comma.

Solution 2:

Grammar Girl did some research and determined that five out of six style guides lean toward using a comma after both i.e. and e.g. Here's the gist of the table she shared on her site:

• Chicago Manual of Style: A comma is usually used
• Blue Book of Grammar and Punctuation: Commas are preferable/optional
• The Columbia Guide to Standard American English: Editors require a comma
• The Guide to Grammar and Writing: The commas make good sense
• Lynch Guide to Grammar: Should be followed by a comma
• Fowler's Modern English Usage: Commas do not usually follow i.e. (No comment on e.g.)

She also gives an excellent rundown on when to use each of these abbreviations. She suggests that you think of i.e. as meaning "in other words" and e.g. as meaning "for example." I recommend reading her entire article.

Addition: My daughter just reminded me of an excellent and entertaining explanation of usage for i.e. and e.g. from The Oatmeal. This one I can't summarize. You must view it in all its glory.