No more Mr. Smartypanties
Why is “bra” singular, but “panties” plural?
Counterintuitive though this may be, let’s start with the panties.
What’s most fascinating about “panties” (okay, maybe not most fascinating, but my mom reads this, okay?) is how a word rooted for centuries in plurality has just in the last few decades taken on more singular uses than it ever had before.
“Panties” of course comes from “pants,” which in turn was rooted in “pantaloons,” originally named for the costume of an Italian commedia dell’arte character named Pantaloon. For a long time pantaloons were plural simply because you had two of them: one for each leg, somehow strapped or fastened in the middle. Not just grammatical, but highly stylish, too.
But considering how long we’ve been wearing ’em, it’s only relatively recently that the singular usage has come into play, and typically only as a modifier: The OED credits the first usage of “panty line” to Woody Allen’s Annie Hall in 1977; “panty liners” are first mentioned in 1983. “Panty raid” first dates to Wisconsin, 1946—clearly some postwar Midwesterners getting loose with their language and morals. A few other usages have popped up here and there, but they almost never stick, probably because they sound weird: panty trunks (1951), panty-belt (1957), panty-blouse (1971), panty-brassiere (1925).
Bras, on the other hand—which come from the French “brassière”—have always been singular garments (two for the price of one!). No extra support needed.
What’s the difference between “i.e.” and “e.g.”?
Both come from Latin, meaning it’s impossible to use either without sounding old and stuffy. But they’re worth knowing, and even more worth getting right.
They’re short for “id est” (translated “that is”) and “exempli gratia” (“for the sake of example”), respectively. Quite simply, “i.e.” is for explanations (“The Angry Grammarian, i.e., the ultimate authority in all things grammatical … ”), whereas “e.g.” is for examples (“Lesser grammarians, e.g., William Safire … ”).
And “e.x.,” used all too often, is for idiots.
Blizzard of Id
You left out the, well, grammatical difference between using i.e. and e.g.: Either can be followed by a list; however, if a list follows i.e. and it’s not exhaustive, then etc. must be used, while etc. is never used with e.g.
It’s true that either i.e. or e.g. can be followed by a list, but where is this etc. crap coming from?
Et cetera—translated literally as “and the rest,” “and so forth,” “and so on”—almost never adds anything substantive to your list. Sometimes it’s necessary, if you have a defined group that’s being described: “The Brady kids (Greg, Marsha, Cindy, etc.) … ” But for most generic lists, leaving off the etc. won’t hurt anybody. Except maybe Jan Brady, who always got the shaft.
So back to your wife’s ridiculous rules: For starters, it’s rare that any list following i.e. will be exhaustive. Since you’re giving explanations that illustrate whatever you’re i.e.-ing, you can almost always list one more reason. So does that mean that nearly every i.e. list is going to have an etc. at the end of it? Seems wasteful.
As for the claim that e.g. can never be followed by an etc., um, says who? There’s nothing inherent in exempli gratia that precludes et cetera, excepting the fact that too much Latin in one sentence is almost as pretentious as arbitrary, meaningless, not-doing-anything-to-aid-understanding grammar rules.