Classics 22: Etymology

Grimm's Law identifies some sound changes that distinguish Germanic languages from the Proto-Indo-European language they split off from. Those changes all occurred in pre-history but left evidence today.

A sound shift occurs when 1) in some particular situation, one phoneme shifts to another phoneme, and 2) every word that includes that phoneme comes to be pronounced with the other phoneme.

The discovery of these sound phenomena occurred near the very start of the science known as comparative historical linguistics, which got its start when Sir William Jones who had been a judge in British-controlled India came back to the motherland and gave a lecture at the Royal Asiatick Society around 1800. He claimed that Sanskrit, Latin, Greek, and German were all related languages, presented some evidence for his claims, and others followed that breadcrumb trail to discover these sound shifts that are called Grimm's Law. First Rasmus Rask, and then very shortly thereafter Grimm (of the brothers Grimm, of fairy tale fame: yes one of those Grimms) discovered these things. Grimm was much more famous and so he got the credit.

In terms of theory, comparative historical linguistics is one of the simplest sciences you will ever encounter. It starts with two things: observed similarities (datasets of words with similarities like the one we just saw in a previous document), and a hypothesis, that common descent is the reason for those similarities. Then, by means of postulated sound shifts, it explains how the forms in the datasets are related.

In some cases, Modern English includes many examples of descendants of the same Proto-Indo-European root word in different forms, some of which underwent these shifts, others of which did not. Of those that underwent these shifts, all are considered to have been in the Proto-Germanic language. Some underwent further changes, while some did not.

From: https://pages.uoregon.edu/webling/sheets/sheet132.htm

1. Voiceless stops /p/, /t/, /k/, and /kw/ become voiceless fricatives /f/, /th/,  /h/ and /wh/.
   
•  /p/, /t/, /k/, and /kw/ as in pop, tot, caulk, and quaquaversal (or quack quack or quote) respectively.
  
• They are called "stops" because they involve a stopping of the flow of air through the mouth.
• They are called "voiceless" because they do not involve vibration of the vocal cords.
• voiceless fricatives are /f/. /th/, and /h/ as in fuzzy, thin, and hi, respectively.
• They are called "fricatives" because they involve friction of air in a narrowed passage of the mouth.
• if all that confuses/annoys you, just think that p's became f's, t's became th's, k's became h's and kw's became wh's!
  

2. Voiced stops /b/, /d/, /g/, and /gw/ became voiceless stops. That fills the vacuum. Phew!
   
• The voiced stops affected are /b/, /d/, /g/, and /gw/ as in bob, dawdle, goggle, and the way Elmer Fudd pronounces grosgrain, or maybe like the middle sound in 'segue' or 'segway' or 'bigwig.'
  
• "Voiced" because they involve use of the vocal cords.
• The four sounds that shifted are those in the table below.
  

3. Voiced aspirated stops became plain voiced stops. That fills the vacuum. Phew!
   
• English does not seem to have voiced aspirated stops of this sort currently: they all changed, and those phomenes just disappeared. RIP phonemes.
  
• "Aspirated" because they involve significant expulsion of air (another way to say it is that they combine the plain voiced stop with an /h/).
• NOTE: these sounds do still occur in English here and there, but they are not separate phonemes: they don't make meaning: they are just allophones of b, d, g, and gwh (actually. can't think of any examples of that last one at all: can you?)