The poor apostrophe!
Just THINKING about the many ways I've seen this abused sets my teeth on edge, as it does to anyone with a modicum of proficiency in the English language.
For those of you who don't have that, here are a few simple rules.
1. Plurals are never made with apostrophes. EVER. EVER. EVER.
In other words, if you see (as I saw this week on a choral schedule sign) "solo's" indicating that the group was going to talk about people auditioning for SOLOS, and you have to physically restrain yourself from getting up and rubbing out the apostrophe on the white board (as I did), you're not being "picky" or "pedantic" or "fussy." You're being literate. Congratulations to you. You know better than probably 90 percent of the allegedly English-speaking population out there. (The foreigners I know for whom English is a second language, by and large, get this right. Go figure.)
2. Plural possessives put the apostrophe after the s. Not before it.
In other words, if you're going to visit the Johnson family, you're going to the "Johnsons'," not the "Johnson's." If only one Johnson lives there, you might be able to get away with the second construction. On the other hand, if only one lives there--say, Abby Johnson--you're probably saying, "I'm going to Abby's house," not, "I'm going to Johnson's." If you're a young man and you commonly call your friends by their last name, you could say the latter...but it would still be more correct to use the former, since your friend Johnson probably hasn't banished the rest of the family from "his" house forever and taken sole possession of it. Get it?
3. It's WOMEN'S clothing, but LADIES' attire.
It's CHILDREN'S clothing, but CHILD's play.
It's MENSWEAR, but MEN'S conference.
Yes, there are irregularities here and there. Deal with them.
4. Finally, speaking of the "conference" example above...
Maybe it's just me, but it seems more correct to place an apostrophe in that "possessive," even though it's largely omitted. Things like "writers conference," although considered technically fine...grate my teeth. Is it a conference of writers? Yes. Is it a conference designed for writers? Yes. If those things are true, don't the writers, in effect, own it? So in that case, to my way of thinking, the term should read "writers' conference." (And, no, not "writer's conference"...unless, again, only one writer is there or "owns" it or goes to it. Which makes it a really, really, really small conference.)
5. Most of all...just remember. Please. Remember.
APOSTROPHES ARE NEVER USED TO MAKE A PLURAL. EVER. EVER. EVER.
I fully expect many of you to be traveling with Sharpies now, ready to jump on and correct those illiterately-produced signs, memos, and other nonsensical notices that say things like "Buy one, get one free on Friday's," or "Tomato's on sale today," or "All permission slip's due tomorrow."
They're everywhere. You know it, and I know it. Do your part.
Me, I have to go take a Valium now.