The rest is sibilance.

So how did I get onto Mrs. Grimsdyke?

(With a fork-lift truck. Bwaaaa-ha-ha-ha-ha!)

But I digress . . . No, it was back when in the comments to an earlier post, I mentioned Gene Wilder's movie The Adventures of Sherlock Holmes' Smarter Brother. And I noticed the possessive.

My Mrs. Grimsdyke was probably a man. (I don't mean she was a cross-dresser; I went to a boys' high school and the masters were all men. Well, they wouldn't be masters if they weren't. Although we did once have a substitute math teacher who was a hundred-year-old woman who made us call her "ma'am.") My vagueness is only because I don't remember which particular English teacher taught us how to form the possessive of word ending in 's.'

(Shout out here to my tenth-grade teacher, Robin MacGibbon, who's the reason why I'm a writer now.)

I learned all those arcane rules about adding the apostrophe only, for both plurals and words with an s-sound at the end -- the boys' bedroom, Dickens' Bleak House, Vaughan Williams' "London" Symphony, Shakespeare's sonnet "My mistress' eyes are nothing like the sun." And naturally, like a good little acolyte, I would defend this to the death.

But one day, I defected. (That's defected.) Because I realized the people who added an apostrophe 's' to all names weren't acting out of a pathetic ignorance of the English language. (Or to put it another way, they weren't just being American.) This was actually an alternative rule, constantly and consistently applied. And -- shades of St. Paul on the road to Damascus -- it suddenly made sense.

Take, for example, a restaurant I used to go to a lot in Greenwich Village, called "Gus's Place." If you used my classical form of punctuation, it would be "Gus' Place," which you'd have to pronounce "GUSS PLACE." But nobody does. They all say "GUSSIZ PLACE." And it's ludicrous to write it one way and say it another. Gus already knows this.

So I dumped my crumbling belief -- noblesse oblige -- and from now on, all plurals get an apostrophe only, but all names and singular words ending with the 's' or 'z' sound get an apostrophe plus an 's.' Simple.

And I immediately had one of those encounters of the Grimsdyke kind with a fellow mother at the local elementary school, who still espoused the classical approach and claimed her authority from the fact that her child had two names that ended sibilantically. (Just made that word up.) Say the kid was called Chris Ferris. She said it would therefore be "Chris' recent arrest," "Chris Ferris' juvy record."  Yeah, but you're saying CHRISSIZ, for Chrissiz sake, I diplomatically explain, so write it that way. I was met with the blank stare of the undeprogrammed cult member.

Here's why I like the alternative rule. It reflects widespread general usage. And it can be used without ambiguity and almost without exception. Some people say we still have to apply the old rule occasionally to deal with the odd tongue-twister. I don't think "Aristophanes's The Wasps" (ARISTOPHANEEZES) or "Socrates's legacy" (SOCRATEEZES) is that hard to say, but I'll defer.

They key thing, as the Hatter might have accepted it, is to say what you mean, and then write what you say.