You’ve probably heard of the Brothers Grimm in conjunction with fairy tales. They were four-handedly responsible for popularizing most of the ones we know and love today. Well, popularizing them for those of us who live outside of the German countryside. If you’ve ever read or watched Sleeping Beauty, Snow White, Cinderella, Rapunzel or Rumpelstiltskin, you’ve got them to thank.
But this is a linguistics blog, not a folklore blog, so why am I going on and on about these guys? Because they were also pretty awesome linguists. They were like the Galileo of linguistics, way ahead of their time and brilliant. They were so brilliant, they discovered something called Grimm’s law. Well, really it was Jacob who discovered it (hence the apostrophe placement) and it wasn’t called Grimm’s law at the time. It was just something that no one had ever thought to look for.
What was it?
Grimm’s law is the very first time we see a set of rules governing linguistic change. And that may sound kind of boring, but it was just as monumental as the discovery of calculus. (Was calculus more of a discovery or a development? Mhh, whatever.) It fundamentally changed the way that linguistics was done.
Basically, Jacob determined that, historically, certain sounds in Germanic languages (including German and English) had changed. And they hadn’t changed randomly. A had changed to B had changed to C across a set of languages, and all across the language. It would be like if three or four different countries, without talking about it, decide that purple was better color for stop signs than red or bright green, and changed out all their stop signs. And then, when they were done, they decided that they really liked pink better and all changed to that.
Why was this exciting? Well, unlike theories like “This word is fun to say becuase I think it is“, Grimm’s law is testable. You can go out and take a picture of some non-pink stop signs and use that evidence to argue against a law that ends with all stop signs being now pink. We have a theory (and phonological theory!) that we can use empirical data to prove or disprove. It obviously took some time to be accepted as the standard practice, and for a long time, all anybody wanted to talk about was historical sound change and written texts. But, hey, once phonology was born, it was only a matter of time before it started saving the world.