How is language evolving on the internet? In this series on internet linguistics, Gretchen McCulloch breaks down the latest innovations in online communication.

You've seen them: Legit. Jealz. Rad. Totes. Def. Obvs. Probs. Whatevs. Proj. Tomorrs. Ridics. Fav. Dece.

But you may not have known that there's a word for them: abbrevs. (And abbrev is itself an abbrev, obvs.) Linguist Rebecca Starr points out that while there are some earlier abbrevs, like commish (from commissioner) from 1910 and delish from 1920, the current abbrev trend has been increasing since the mid-2000s.

The interesting thing about abbrevs is that they're based on sound, not on spelling. Just think about how we have to respell certain words when making them into abbrevs, such as delish, presh, profesh, unfortch, and sitch. And with words like funksh (function), relash (relationship), fuche (future), natch (naturally), or sosh (sociology), you might not even be able to tell from the abbrev what the original word was.  

But the worst one for spelling is the abbrev of usual. Try it:

"What'll you have?"

"Oh, just the...use? The uzh? The yooz? The usj? The yoozh? The yooj?"

You know how to say it, but the sound that the "su" makes in usual normally comes from isn't one that we've got a good way of writing in English. Same goes for the abbrevs of casual or pleasure which end in the same sound. Caj? Plezh?

What all these respelled abbrevs have in common is that they contain a "sh" or "ch" or "zh" sound that wasn't originally there in the history of the word—as we can still see in the spelling. But when generations of people pronounce a t or an s or a z sound right before a y sound very quickly, the two of them stuck together into that sh/ch/zh—just like how "got you" becomes "gotcha" or "did you" becomes "didja." Which would be fine, except that the second half of the word that's contributing the "y" sound gets cut off when you abbrev it, hence the spelling changes. (And Lane Greene at The Economist suggests that this weird sound change is part of the appeal for many abbrevs.)

But how do you decide what to cut off in the first place? After all, a lot of abbrevs are one syllable, like jeals, rad, totes, def, obvs—but some of them are two syllables, like delish, legit, profesh, and abbrev itself. And you can't just swap them: radics, totals, defin just sound weird, while prof, abs, dels, leg might be abbrevs of something, but they sure don't correspond to delicious, legitimate, professional, or abbreviation.

It has to do with stress. Think about how you say the word "totally"—TO-tal-LY, not to-TAL-ly—it becomes "totes" by clipping off that first, stressed, syllable. But when you say "legitimate," you say le-GI-tam-ATE, not LE-gi-TAM-ate. Clipping off the unstressed syllable at the beginning just isn't enough—you need something that's stressed too, so the second syllable comes along to make "legit."

The stress thing explains why some words just don't abbrev: "interesting" should cut off at "int" but that's just not different enough from "intense" or "internet" or a whole bunch of other words that begin with int-, so we don't even try any of them. And it also tells us why there aren't any three-syllable abbrevs: English words get some kind of stress every other syllable, even if it's just secondary stress.

Perhaps the best part of abbrevs is how they intersect with other slang, like acronyms. Most of the time, you just add an s or a z to the end of the acronym without actually abbreving it at all, as in lols and omgz, but acronyms with w are special. The best known are BTdubs (from "by the way" via BTW), dubsTF (from WTF), and FTdubs (from "for the win" via FTW), but I also found people on Twitter using OMdubs ("on my way" via OMW), BMdubs (BMW, as in the car), and even one guy who uses FWIdubs ("for what it's worth").

The "dubs" abbrevs really put the lie to the idea that people abbrev just because it's easier, since all the w acronyms are actually shorter than their "dubs" versions. It's more about the fun of creash, natch.