Here's one Sasha came up with -- what do these have in common, and can you name more?

  • Die.

  • Medium.

  • Person.

  • Penny.

gvibes (mail):
I wwas with you until "Penny." How about "datum"?
6.22.2006 2:52am
Patrick McKenzie (mail):
These all have irregular plural forms (dice, media, people, *pence*). Another example would be goose (geese).
6.22.2006 2:53am
John R. Mayne (mail):
Are these British pennies?
6.22.2006 2:54am
Patrick McKenzie (mail):
I suppose you could add a lawyerly disclaimer that any of these words can be pluralized both by addition of s and by the way I described above, although it changes the meaning in some cases.

dice: You get two of them with a game of Monopoly. dies: You can order two of them from a machine tool shop, although you'd better be Uncle Pennybags.

media: In the business of finding things out they are not supposed to know. mediums: In the business of making it appear to you that they know things they are not supposed to know.

people: You probably know several. persons: If you know any, they're likely in trouble or you're far too educated for your own good and could use some loosening up.

pence: 90 of these will buy you a cup of coffee in Britain. Pennys (note capitalization in original): referring to the Penny family or multiple members thereof (as in the 1918 novel "Three Black Pennys".

If you accept alternate interpretation B, another word which follows the pattern is mouse: mice are rodents, mouses are input devices (note that many people and authorities will also accept "mice" to indicate a plural quantity of the type of input device memorably dubbed the "X-Y Position Indicator for a Display System").
6.22.2006 3:14am
roy (mail) (www):
I think these all have proper irregular and regular plural forms, if you accept homonyms. Dice/dies, media/mediums, people/persons, pence/pennies.

So datum and goose would be out.

6.22.2006 3:21am
roy (mail) (www):
Awh, Patrick beat me. I took too long poofreading.
6.22.2006 3:22am
A Person:
people: You probably know several. persons: If you know any, they're likely in trouble or you're far too educated for your own good and could use some loosening up.

Actually, though "persons" sounds overrefined when referring to human beings, I think it's the normal way of pluralizing the grammatical term: "English verbs have the same form in the first and second persons." As opposed to: "The first and second people were Adam and Eve."
6.22.2006 3:22am
Patrick McKenzie (mail):
A Person: You're right, I rather like that as it makes the explanation simpler. On reflection, I also forgot the usage "in the persons of" (c.f. Common Sense) and "on their persons" (Q: "Where did you find the contraband, officer?" A: "On the subjects' persons.").
6.22.2006 4:22am
Apollo (mail) (www):
The best description of persons vs. people comes, of course, from Strunk &White:

The word people is best not used with words of number in place of persons. If of "six people" five went away, how many people would be left? Answer: one people.
6.22.2006 6:11am
Dick King:
datums are reference geometric points on the surface of a planet. For many examples, see here.

6.22.2006 11:19am
Eh Nonymous (mail) (www):
Apollo: on the contrary. Ask any poorly programmed computer. Take one away from two, and they often leave you with "one thingummies."

Also, S&W is tiresome. Witty doesn't mean right.
6.22.2006 11:21am
Do you count stuffy Latinate plurals? E.g. index, antenna.
6.22.2006 11:51am
Maniakes (mail) (www):
All those things have been in my kitchen.
6.22.2006 12:28pm
Silicon Valley Jim:
Somewhat OT: the plural of the mouse that eats cheese, can be caught in traps, etc., is mice. In at least one major electronics store here in SV, the plural of the mouse attached to my computer is mouses.
6.22.2006 12:37pm
Greedy Clerk (mail):
In response to Silicon Valley Jim: I work on a case involving computer mice, and we often have this debate -- is it computer "mouses" or "mice"? Both parties seem to have settled on computer mice in court filings, but industry usage is inconsistent --- though I think a substantial majority favors mice.
6.22.2006 1:46pm
If dual plurals is the pattern, then "index" belongs on the list. If you don't believe me, google it and see that "indexes" scores 1.381 times more hits than "indices" :-)
6.22.2006 3:49pm
Michelle Dulak Thomson (mail):

I took too long poofreading.

Now, that is just lovely. Whether intentional or not!

ys: You're right, I'm afraid; "indices" is practically extinct as plural for "index" in the thingummy-at-the-back-of-a-book sense. Use it that way and you get the same funny looks you do when you treat "data" and "media" as plural nouns. Parallel cases (matrices, vortices, &c.) seem to me to be in better shape, but that's probably just because the words themselves are less common.
6.22.2006 4:24pm
James Taranto (mail) (www):
How about "ice cream" or "ax"?
6.22.2006 4:51pm
"Goose" does work.

tr.v. Slang goosed, goos·ing, goos·es

1. To poke, prod, or pinch (a person) between or on the buttocks.
2. To move to action; spur: goosed the governor to sign the tax bill.
3. To give a spurt of fuel to (a car, for example); cause to accelerate quickly. “The pilot goosed his craft, powering away” (Nicholas Proffitt).
6.22.2006 7:29pm
I think what EV may have been hinting at was the whole "common usage" versus "correct usage" thing. For instance, most people say "dice" even when it is singular (except me, but I am a geek.) Many people will refer to "media" as a singular term (again, I claim exception). As for "person," I think most persons of moderate education will say "people" where "persons" is the preferred usage. But when it comes to "penny" my theory breaks down. Unless we want to use English pennies, in which case I heard the term "a one-pence piece" many a time growing up in England. In fact, they used to have a "half-pence piece," a denomination of currency that they stopped producing in the early eighties.
6.22.2006 8:28pm
Sasha (mail):
I should mention, before everyone goes off on a different track: Dual plurals isn't the pattern; different plurals for different meanings is the pattern. "Datum" looks O.K. and so does "index"; no on "goose" (one of them is a verb), "fish" ("fishes" isn't a different meaning but just a different usage), or "mouse" (computer mice seems to be widespread).

Anything else? I have three other examples in my pocket, but I'd be interested to see what others come up with.
6.22.2006 8:29pm
As for part two of the question (other examples of same) I can only think of one offhand: datum. However, even that is in contention.
6.22.2006 8:33pm
Eugene Volokh (www):
I say "louse."
6.22.2006 9:25pm
Josh Warneke (mail) (www):
You've missed the obvious: each word contains the letter "e". ;)
6.22.2006 9:44pm
Eugene Volokh (www):
Might "brother" also qualify?
6.22.2006 10:24pm
randal (mail):
Dude: For some reason I know a bulk of ichthyologists and "fish" does not mean the same thing as "fishes".

It's that in-between category where one is the plural and the other means more than one category. You could catch all the fishes in the sea by catching one of each kind. Maybe it counts as jargon, but I trust the ichthyologists on this one.

Kindof like "water" versus "waters", "hair" versus "hairs", "oil" versus "oils", or "time" versus "times" (which themselves are all slightly different). More like "grass" versus "grasses" if there were such a thing as one grass. Also I've never been sure what "sands" are, if anyone can explain it. Seems like you could do a lot there... "the sands of time", "the sand of the times", "the time of sand"... Ok, enough of that.
6.23.2006 4:11am
What about arm?

Arms and armies.
6.23.2006 1:19pm
I guess that doesn't count. The singular would have to be the same to fit your criteria.
6.23.2006 1:25pm
Octopus? (Plural is "octopuses" when you're talking about individuals, and "octopodes" when you're talking about species.)
6.23.2006 2:56pm
Syd (mail):
Goose does work since you can give somebody two gooses and they would be rather angry at you.
6.24.2006 3:32am
Lucian Chimene (mail):
Re: ". . .'indices' is practically extinct as plural for 'index' in the thingummy-at-the-back-of-a-book sense."

According to a friend, when she studied Latin the girls in her class had a bit of naughty fun extrapolating from 'index/indices' and 'codex/codices' to Kotex/Kotices. No word on whether they got to "Tampices."
And once I heard a twit in the office where I worked mention certain 'indices' and then single out for our edification one particular 'indicee.'
6.24.2006 9:47pm