The non-word nerds in my office often have trouble with what they perceive to be a lack of consistency regarding certain grammar rules. (Apparently, consistency is a thing in design.)
For instance, they don’t always understand how man-eating chicken is different from man eating chicken. Or why Southern California is correct, but Eastern Wyoming isn’t. Or how Strunk & White can say one thing while Chicago says another—both of which are correct.
But possessives? That’s another thing entirely.
“If you have ever tried to write about the apostrophe,” writes Mary Norris, “and started out with how simple it is to form the possessive of singular and plural nouns and then thought of a few exceptions…you know despair.”
I’m not complaining. Far from it. After all, it it were easy, I wouldn’t have a job.