For whatever reason, people seem to confuse (and maybe conflate) forming possessives of plurals with forming possessives of proper nouns ending in -s. I’m hoping to untangle the concepts for them with these last two posts (today’s and the previous one).
First, what’s a proper noun? Well, the easiest example is your own name. Karen is a proper noun. Fred is a proper noun. Oktober is a proper noun. How do we make those into possessives?
Simple. Add an apostrophe and an S.
You won’t find any contradictions in any style guide to that rule. It’s super simple.
It gets sticky, though, if the proper noun ends in an S.
Which is right: James’, or James’s?
Both. There’s not a damn thing wrong with either version. The Chicago Manual of Style has adopted what is to me a very logical guide: if you say it, write it. We say the last S in “James’s,” so that’s what CMoS calls for.
If the name ends in an -eez sound, you also use an apostrophe and an S. “Xerxes’s troops.”
If the name ends in a silent S, you still use the apostrophe and the S, because you’ll pronounce that final S. “Descartes’s hypothesis”
The former guideline about “historical names” is no longer included as of the 17th edition. (It might have gone away in the 16th, but I don’t have that handy.)
They do provide an alternative guideline, which omits the S from all names ending in an S. However, they also restate their guidance that if it’s pronounced, it should be written, and therefore this alternative is “therefore not recommended.”
Y’all should know by now that I’m a CMoS gal. Of course, if you’re being paid to use AP, or APA, or MLA, or what have you, that’s whose guidance you should be following on this matter. In any case, I strongly recommend ditching whatever you think you remember from your salad days (mine were mostly made with rancid Miracle Whip) and that English teacher who smelled either of Shalimar or English Leather (or, if you were really unlucky, Wind Song or Hai Karate), getting yourself an up-to-date style manual or a copy of June Casagrande’s The best punctuation book, period. (When you see it,l you’ll understand why I styled it that way and not the traditional all-italic way.) In all honesty, I reference my copy of that more than I do CMoS because it’s much easier to find what I’m after. (The really esoteric stuff I still use CMoS for, but not the everyday stuff.)
I hope this has helped unmuddy the waters. By all means, if you have questions, leave a comment or hit me up on Twitter. I do my best to answer in a timely manner.