A man in England runs something called the Apostrophy Protection Society. And I wish him the best of luck.
His general approach is to educate, not berate. But in my view, education's overrated. Sometimes a little well-placed beratement can accomplish more than endless attempts at education. It's not like these folks going around abusing apostrophes haven't heard the rules before. I mean, there are only two of them:
- If your subject is singular (or irregularly plural), add an apostrophe AND AN S.
- If your subject is a regular plural, add an apostrophe.
Bob and Sally Jones own a house. They are the Joneses, and it is the Joneses' house. Bob parks his car at work in his personal parking spot. He is Jones, and it is Jones's parking spot. ALL THREE words, Joneses, Joneses', and Jones's, are pronounced the same: JONE-zez. When you write Jones' you are saying there is something called a Jone, and that several of them collectively own something. Since this isn't what you mean, this isn't what you should write.