A friend and I recently had a discussion regarding the Toyota Prius, the hybrid automobile from the Japanese car manufacturer. Somehow in the course of our discussion, I pluralized the word Prius by calling it Priuses. My friend corrected me by telling me the pluralization of Prius is actually Prii–I didn’t offer much of a protest because I wasn’t sure at the time, and she is, after all, the owner of one; hence she has had many more discussions about the car than I. However, curiosity did get the better of me, so I decided to set out on a journey–and by journey, I mean using Google–to get to the bottom of this matter.
First, I checked the Wikipedia entry for the Toyota Prius. There is a section with the etymology and terminology of the name. The word prius is latin, and it means “before,” with priora being its plural. However, Toyota decided to let the public choose what it wanted for the pluralization of Prius by holding a voting campaign. The five candidates were: Prii, Prius, Priuses, Prium and Prien. On February 20, 2011, Toyota announced the winning name was Prii, which had 25 per cent of the votes (Prius was a close second with 24 per cent). So there you have it, Prii is “the term recognized by Toyota” as the pluralization of Prius.
I thought all matters were settled until I came across this article here. I happened to scroll down to the comments’ section and noticed one from a gentleman with the nomme de plume Bob. He pointed out Toyota’s voting campaign for the pluralization of Prius was nothing more than a marketing gimmick. Bob was kind enough to provide a link to an article on Grammar Girl’s website with rules on how to make family names plural.
Okay, so how is making family names plural even germane to pluralizing the Toyota Prius? This section provides the connection:
First let’s figure out how to make family names plural. Family names are like brand names, you don’t change the base spelling. For example you make “blackberry,” the fruit, plural by changing the “y” to “ies”; but you make “BlackBerry,” the phone, plural by simply adding an “s” to the end: “BlackBerrys.”
When it comes to names or brand names that end with an “s,” such as a certain hybrid vehicle from the land of the rising sun, an “es” is added to the “s.” Therefore, to correctly pluralize Prius, one would call the two or more vehicles Priuses. I’ll inform my friend about my important discovery regarding her car, but I don’t want to be smug about it.