How about the noun "data." What's its number? Is it singular? Plural? If so, why so?
The Associated Press says, without equivocation, that "'data' is a plural noun that normally takes plural verbs and pronouns." Then the AP waffles: When "data" is treated as a unit, the data IS sound. When data are treated as individual items, the data ARE carefully collected.
All clear? We're talking today about familiar English words that stay tangled in their foreign roots. A huge number of them date from the Romans 2,500 years ago, another substantial number from the ancient Greeks. They're all mixed in with contemporary foreign phrases.
Backing away from the AP, The New York Times treats the plural noun "data" as a singular noun that's been mugged. Your dear old high school Latin teacher may cringe at "The data IS persuasive," but that's the way the souffle falls. The noun has become "acceptable" as a singular term for information, e.g., "The data was persuasive." When "data" is hired to define a collection of some kind, the Times' style manual says, "the noun can still be plural," e.g., "The data arrive from bookstores nationwide." All clear? The Times' entry concludes with a gratuitous sneer at the singular "datum," a word "both stilted and deservedly obscure."
The lexicographer Bryan Garner, my favorite contemporary authority on these matters, has all but yielded the field. These days, he agrees, "datum" is "likely to sound pretentious." My advice is to rely absolutely on your ear. It will tell you when the data is and when the data are. There isn't any ironbound rule.
On many other classic words the rules are more prescriptive than permissive, e.g., one phenomenon, two phenomena; one criterion, two criteria; one bacterium, two bacteria; one addendum, two addenda; one male alumnus, one female alumnae. An "agenda" hasn't been a plural noun for years. As for the media, bless us, we are forever plural.
Sixty years of editing copy -- my own copy and other writers' copy -- have taught me a lesson for writers of all ages everywhere. Let me pass it along: Unless you are confident of your mastery of a foreign language, don't trot it out in public. Instead of providing that soupcon of sophistication, that lovely little apercu of wit, you are likely to wind up with scrambled oeufs on your figure. (Among the other hazards of foreign quotation is the typesetting problem that accompanies the diacritical mark. Without their cedillas, those sexy nouns look half undressed.)
If you want to quote foreign, you ought to spell foreign. It is a rule! Five years ago the outgoing president of the South Carolina Medical Association failed to observe the rule. He thought to end his valedictory editorial by quoting the state's Latin motto, Dum Spiro Spero . (While I breathe, I hope.) Sad to say, it came out "Dum Sprio Spreo," which sounded like a vegetable oil or a one-time vice president.
"In a sense," wrote columnist George Will, "the sturm and drang about this contest ..." The rule on German nouns is to capitalize the burly fellows. That goes for Zeitgeist and Schadenfreude, too.
If you are tempted to quote French phrases, I have some advice for you: Lie down until the impulse goes away. A snack by any other name is not usefully an amuse-gueule . Not everyone has met a roman a clef or punctuated it properly either. If you absolutely must speak of hoi polloi , do not speak of "the" hoi polloi. In sum, dear friends, stick with English unless you know an umlaut from a virgule, and back again. Viola! (STET!)
By the way, assorted regular features like Classical Words of the Day, This Day in Ancient History, etc., will be resuming in the next couple of days. For those of you who have asked for a separate rss feed for This Day, I figured out how to do it and now have it on my to do list.