I just realized the other day that I have no idea what these abbreviations mean. In fact, I can’t even look them up, for the same reason.
I am also aware of their meaning only through context, and then vaguely. From what I can tell, “i.e.” somehow means something like the phrase “that is,” although damned if I can see how.
Likewise, “e.g.” means something like “therefore,” and “et. al.” means “and so forth.”
Once I started thinking about this, I realized that never in my entire life had anyone told me what these little abbreviations meant. I’ve seen them in things written by other people, and sort-of knew what they meant. But now I REALLY want to know. Do the letters stand for some complete phrase in Latin? What is that phrase? How does it translate?
i.e. is latin for “id est” which means “that is”
e.g. latin for “exempla grata” (or whatever spelling…), basically means “for example”
et. al. means “and others” though I’m not sure of the exact word al stands for.
I guess I meant I don’t know what words the abbreviations apparently stand for, because I do have some idea what they mean.
top of head:
i.e. is “id est”-- or “that is”
etc. is “et cetera” --“and following” (?)
wait, I’ll look em up: not “following”: “and the rest”
e.g.: “exempli gratia”-- “for example”
et al. : “et alii”-- “and others”
you use “etc.” for non-human nouns; et al. doesn’t mean “and so forth”; it specifically refers to people.
Thanks, Garfiled! Boy, that was fast.
Oips.
by the way, there is no period after “et” in any of these; et is a whole word, not an abbreviation.
See, lissener, that’s what you get for looking things up!
I thought “et al.” was an abbreviation for “et alia” - same word as in the phrase “inter alia” [[amongst other things"].
et al. = et alia (“and other things”)
or
et al. = et alii (“and other people”, especially when referring to males or a mixed group or a group of indeterminate sex)
or more rarely
et al. = et aliae (“and other people”, referring to a group that is known to be exclusively female)
Eugene Ehrlich, in his book,
Amo, Amas, Amat and More, How to Use Latin to Your Own Advantage and to the Astonishment of Others
(1985 Harper and Row; N.Y., NY)
has this to say about et al.:
"abbreviation of et alii, et aliae, et alia
" This abbreviation is used in writing to avoid a lengthy listing. Et alii (et AH-lee–ee) is masculine, so it is properly used in speech to mean ‘and other men’ when preceded by the name of a male or to mean “and other people.” Et aliae (AH-lee-i)is feminine, so it is properly used in speech to mean ‘and other women.’ Et alia (AH-lee-ah) is neuter, so it is properly used in speech to mean ‘and other things.’ Educated persons do not pronounce the abbreviation et al. ‘And others’ is said for et al."
Here’s a way for non-Latin speakers to remember i.e. and e.g.
i.e. = in explanation
e.g. =example given
Sure, it’s not precisely what they mean, but it’s close enough to keep you out of trouble.
Are you thinking of “ergo”? Ergo does mean “therefore”, in the sense that you’d use it in a logical argument. For instance, in Descartes’ “I think, ergo I am”, the implication is “I think. Because of the fact that I think, I know it is true that I am.”, not “The reason for my existance is thinking.”. But so far as I know, “ergo” is never abbreviated.
I’d like to add that it’s a common copyediting convention to change these to their English equivalents.
Just thought I’d add two more that have always annoyed me.
viz. (videlicet). Means namely.
Use to introduce specifically the items that compose what has been previously expressed as a whole.
N.B. (nota bene) Means note well and does not in any way refer to the element Niobium.
Use to call attention to a point. Unlike most abbreviations from Latin, N.B. is always capitalized N.B.
Al was a Roman citizen who lived from 143 to 91 B.C. He had a very nondescript face.
A relative of viz. that’s encountered only rarely is sc., for scilicet “let it be known”. It’s used to explain obscure or vague words – for example, if a classical text is being discussed and an obscure work is mentioned that would have been known to the author’s contemporaries, one might write “sc., a tragedy set in Mycenae which has been lost.” I only ever saw this one in the Oxford English Dictionary.
And there’s vide or v. for “see”, and vide supra/infra for “see above/below”, and q.v. for quod vide “which see”.
People often confuse i.e. and e.g.; the meaning is not the same. i.e.–“that is” – means one refers to a specific thing, while e.g. means that one is stating one example of what is being discussed, with the assumption that other examples exist and are also being discussed.
Conrad Verloc: It is not my experience that ‘educated people’ replace these abbreviations with the English equivalents in speech. I’ve heard many references to journal articles as “Paabo et al.” (though the usual practice is to use just the name of the first author listed).
Chronos: Descarte’s cogito, ergo sum implies that because he knows he is thinking, he knows at least that he exists, but cannot be certain about anything else, because his senses could be being deluded entirely by an evil demon. At least that’s what they told me when I was reading Meditations – the Cogito is from Discourse on Method, which I didn’t read.
Scarlett nails it - it’s also common among technical writers (of which I am one) to avoid using these abbreviations in favor of their common equivalents. That is, if you want to write, “for example,” you write, “for example.” Technical writers do this because a) there is confusion as to what the abbreviation means, and b) it takes longer for readers to puzzle out the abbreviation than simply read and quickly understand the more common equivalent.
So if you’re writing something, don’t use them. Your readers will thank you.
Snicks
What’s “ïnfra dig” (?)?
Infra dignitatem - beneath one’s dignity.
As in, some Dopers apparently find consulting a dictionary for these everyday abbreviations to be infra dig. 
There is also ibid. Dunno what it satnds for, but one place you use it is with footnotes. It means this footnote comes from the same source as the last one.
made up example:
The average elephant weighs more than the average shrew(1). but less than the average blue whale(2)
.
.
.
(1) Fred Smith’s Amazing Animal Facts, page 23
(2) ibid
Brian
(hope I got that right)