OK, I was wrong. But I’m not the only one: Many other authorities on English grammar made the same mistake I did.

Here’s what happened. I’m the sponsor and resident grammar authority for a writing club. At today’s meeting, member Richard Ricketts asked me a provocative question: Do possessive pronouns ever have apostrophes?

My immediate answer was no. His doesn’t have an apostrophe, and neither do any of the other possessive pronouns: hers, yours, ours, theirs, whose, its (it’s with an apostrophe means it is).

He nodded – and then he asked me about one. Suppose you wrote a sentence like “One’s handkerchief should always be clean.” Apostrophe or not?

I gulped. We checked the dictionary. Sure enough, one is classified as a pronoun in that sentence (it can also be a noun and an adjective, depending on how it’s used). And yes, the possessive form gets an apostrophe: one’s.

Score one for Richard Ricketts. And deduct a point from anyone who thinks that learning complicated grammatical classifications makes writing easy. Richard’s question underscores what I’ve been saying for years: Learning all that theory just muddies the waters.