Q: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
Should e.g. and i.e. have periods, e.g. 'e.g.', or no periods, eg 'eg'? Should they be italicized, e.g. 'i.e.' or not, eg 'i.e'?.
A:
In formal contexts, I would go with 'e.g.' and 'i.e.', with two periods and without a whitespace. The spellings without periods are quite popular, but informal. For example, Merriam-Webster does not have an entry for either 'eg' or 'ie'. Wiktionary marks 'eg.' and 'eg' as informal, and offers the following usage notes: Opinion is mixed about whether this term should be italicized as although it is Latin, it has become part of standard English, and whether it should be written with a separating space 'e. g.' as it was originally two separate words. It also offers the following usage notes for 'i.e.': Opinion is mixed about whether the abbreviation should be italicized, or whether there should be a separating non-breaking space as in i. e.. ie is often found in current usage, and is perhaps now considered acceptable. Personally, I would argue that there's no need whatsoever to italicize 'e.g.' or 'i.e.'. Both expressions are extremely common in English, and have been for a long time. They are full-fledged citizens of the English language, and as such, they do not have to be italicized as if they were foreign words.