Y not Y?

I used to frequently walk by a sign advertising  the “Slush Puppie” brand of crushed-ice drinks. The odd spelling bothered me partly because the corporate symbol is a dog—a puppy—and partly because the name is a pun on hushpuppy: both of them with with Y endings. In these and many other words the Y changes to IE only when pluralized: puppies and hushpuppies.

Was the brand name influenced by the fact that the generic term for the drink is a slushie rather than a slushy? Even its more sophisticated relative is a smoothie—not a smoothy (a smooth-talking guy) .

Of course brand names often use nonstandard cutesy spellings such as “Krispy Kreme,” but notice that even in this famous instance the -Y suffix from crispy remains. The spelling only changes to -IE when pluralized, as in Rice Krispies.

There are other instances in which the two suffixes have different meanings. Although usage varies, usually a caddie carries your golf clubs and a Caddy is a car. Cadillac doesn’t make golf carts. A fish caught in polluted water might be a crappy crappie.

Common Errors in English Usage has this entry for hippy vs. hippie on page 143:

A long-haired 60s flower child was a “hippie.” “Hippy” is an adjective describing someone with wide hips. The IE is not caused by a Y changing to IE in the plural as in “puppy” and “puppies.” It is rather a dismissive diminutive, invented by older, more sophisticated hipsters looking down on the new kids as mere “hippies.” Confusing these two is definitely unhip.

Both suffixes are used in people’s names, with -y more common in men’s names and -ie more common in women’s: Bobby vs. Bobbie, Terry vs. Terrie,  Cary vs. Carrie, etc. (To check which spelling is used for a specific gender, type a name into Google and choose “Images,” but don’t search for “carie” unless you want to be grossed out by multiple images of gum disease.)

Female names often use the Y ending too. There is Lucie and Lucy, Katie and Katy, Tracie and Tracy. 

There are variations in adjectives associated with femininity: Bonnie may be bonny or slinky, but also a pixie—a real cutie.

Of course there are many ways to make a traditional masculine name feminine besides changing the suffix (the reverse process is rare) Sometimes they are just appropriated unchanged, as in Daryl, Ashley, Blake, Tristan, Dylan, Nikita, Madison, Lindsay, Ryan, Taylor—the list goes on and on. In other cases names are feminized with alternative spellings: Alex becomes Alix, Joe becomes Jo, and Tony becomes Toni.

I used to have to explain to my literature students that Virgil’s Second Eclogue is a homosexual love poem—they didn’t realize that Alexis had always been a male name until very recently.

But to return to our topic, the Guardian and Observer style guide provides these useful guidelines:

As a general rule: -y is an English suffix, whose function is to create an adjective (usually from a noun, eg creamy); -ie was originally a Scottish suffix, whose function is to add the meaning of "diminutive" (usually from a noun, eg beastie).  

So in most cases, where there is dispute over whether a noun takes a -y or an -ie ending, the correct answer is -ie: she's a girly girl, but she's no helpless girlie. Think also scrunchie, beanie, nightie, meanie ... There are exceptions (a hippy, an indie band), but where specific examples are not given, use -ie for nouns and -y for adjectives.

For a detailed scholarly article on the origins of the -y suffix, see this article.