So what is it about the apostrophe? How come so few people know how to use it? And why do I get so irritated by its misuse?
The rules are pretty simple, insofar as I understand them. Rule number 1: "Its" is "it's" when there's an "i" missing, that is, when it means "it is", NOT when it's simply a possessive, as in "the cat lost its virginity" or "my computer needs its screen cleaned." It is = it's. Easy, no? Also there is = there's, as in "Waiter, there's a fly in my soup." And "Who's coming to dinner?" (Not, please, "whose"!) Or, "Where's my umbrella?" Or "Here's a lovely gift for you." It's "is" with the "i" missing. An apostrophe can also substitute for other missing letters, of course, as in li'l' Abner or young 'uns. (actually, that should logically be 'nes, no? But who says the rules of logic apply to the rules of grammar?) Or, "I'm so happy to see you. Aren't we having a wonderful time? Don't you just love this muggy weather?"
Rule number two: possessives. With a plural noun, the apostrophe goes behind the "s"; if it's a singular noun, the apostrophe goes before the "s". Thus, "It's my dog's birthday," or "It's a dog's life." One dog. But, "I forgot to bring the dogs' leashes"--two or more dogs. ("My mother's in the loo," by the way, is obviously rule number 1, above, unless it becomes "My mother's friend is in the loo.") So if you ask yourself, is this noun singular or is it plural?, and act accordingly, you're going to get it right. Usually. I imagine someone will point out some ridiculously obtuse exception.
(While I'm at it, I might as well mention the habitually misused "fewer" and "less". It's a bit like with the apostrophe. "Fewer" goes with plural nouns; "less" with singular ones. Thus, "There is less sugar in this jar than in the other;" but "There are fewer grains of sugar in this jar..." Why can't people get this right?)
The more significant question, of course, is why I should allow such things to irritate me. Language evolves. It's the commonly-made mistakes that determine the way it changes. Those darn Gauls could not speak proper Latin for toffee, so they turned it into French. It took a while, but it was improper use and bad pronunciation that brought about the change. Besides, who needs apostrophes, really? They should probably accompany the copper penny into long overdue extinction. And no one but me gives a damn about "less" and "fewer." They could care... well, less.
So why? I guess a part of it is that I love the English language, and hate to see it being abused. It's such a wonderful instrument, so precise when needed, so beautiful, so poetic, so amazingly flexible and subtle, so rich with meanings, so infinitely utile. It's also easy to abuse, for anyone who does not care enough to use it well--for those who think it's no more than a tool to convey broad swaths of meaning in the crassest possible way. They forget that a slip of the tongue or a change of tone or emphasis can turn what's intended as a compliment into offense. Politicians discover this sometimes to their cost--Barack Obama's "bitter" slip proved bitter, indeed. People forget that words carry more than simple meanings: they carry emotional values, too, and physical heft. Words, and the way they're said, matter more than people think they do--until they discover, as they sometimes do, that something has gone seriously amiss in their communications. (My father learned this once when insisting on showing off his wildly inadequate schoolboy French: having ordered three coffees for the family at a Brussels cafe, he next asked the waitress for the toilet, pronouncing it "twa-ley." When he returned to the table, he found three cups of milk awaiting him, "trois laits;" he should, of course, have asked for the "twa-lette.")
I know that language changes. I acknowledge that it must. But I'll admit to being a bit of a language snob. It pains me to hear how it's mutilated on the streets, just as it pains me when I see that misplaced apostrophe. There must be some part of me--there IS, I confess, some part of me--that loves the rules. I was too old, by the 1960s, to learn to "question authority"--remember that one?--in that easy, dismissive way that seems to have become a part of our culture. When I question authority, as I actually do quite often, it comes only after an inner struggle with that inculcated habit of respecting it. And obeying it. (To do otherwise, at an English boarding school, was to risk exposing one's rear end to a painful encounter with the cane--or to some other, equally unappealing punishment. At home, little children did what they were told. Rules, my father used to say, are rules.)
And then of course there's that other part of me that hates them, and distrusts whoever is handing them out. The creative part of me, I think, puts both the love and the hate to use. Any poet knows that rules are fun to work with. It's in the tension between their observation and their breach that good things happen, that new ideas are born; between freedom and discipline, the creative imagination and plodding orthodoxy. I'm sure it must be the same with science, indeed with any other intellectual discipline. So I watch my pedantry when it comes to apostrophes and grammatical lapses with both skepticism and fondness. And I continue to wish that people would just speak and write proper, for gods sake, with less mistakes in there (theirs' another one, damn and blast it--don't get me started!) daily acts of casual mutilation.