Well, no, it's not. But you'll see where I'm going with that. Promise. English is an evolving language, as arguably is French, but the rightness or wrongness of word usage in English is all about usage. The venerable OED, my pinnacle for all things English language related is all about usage. Words mean what they do because that's how people use them. End of story. But, people use words wrong all the time. See, I just did it their. And they're.