According to law
Phonetic laws only apply to one language or dialect and are only effective for a limited period of time. Unless a combinatorial sound change is involved, they concern a certain phoneme with usually only a very few exceptions, which can often be explained by certain circumstances.
Examples of phonetic laws
Such a sound law (East Central German rounding, from the 12th century), for example, made the Middle High German phonemes / ø / and / y / coincide with / e / and / i / in many German dialects.
- this - this
- think - think
- thick - thick
- thin - thin
- Thirst - thirst
- three - three
History of the sound laws
For historical linguistics, the postulate of the absence of exception of the sound laws is central. It challenges the scientist to look for sound laws even where they are not obvious. The "absence of exception" forbids the researcher to give up prematurely and to "explain" a development as an exception. On closer study, apparent exceptions often turn out to be sound laws in a somewhat more complicated formulation.
It was the linguists of the Leipzig School , also known as junior grammarians , who made the absence of exception their credo. In the so-called Young Grammatical Manifesto, Karl Brugmann and Hermann Osthoff write :
“All sound change, as far as it is mechanical, takes place according to invariable laws, i. H. the direction of the sound movement is always the same for all members of a language cooperative, except in the event that there is a split in dialect "
With non-mechanical sound change, we mean above all analogy and borrowing . The young grammatical confession is more complicated than it seems, because the “language cooperative” or the boundaries of dialects are precisely defined by the sound laws.
It is certainly most fruitful to understand the requirement of no exception as a methodological postulate. In fact, the young grammarians (and probably the researchers before them too!) Worked practically on the basis of a methodological postulate understood in this way.
On the basis of the absence of exception, the young grammarians branded many word relationships recognized up to their time as "impossible". This word must have been uttered in Leipzig in those years and was repeatedly used against the older linguists ( Georg Curtius , Leipzig, August Friedrich Pott , Halle) by their former students. This dispute between the younger (who were then mocked as young grammarians) and the elderly went down in the history of science as the phonetic law dispute. The classical philologist Georg Curtius broke it off the fence in writing; Karl Brugmann and Berthold Delbrück gave the first answers .
In addition to the fundamental dispute over methods, these writings also dealt with specific differences of opinion. So it became clear to the young grammarians that Sanskrit (Old Indian) was not as original and conservative as had been believed until then. The previous generation of researchers had believed that the a -According of Sanskrit in many European languages such as Latin or Ancient Greek to e or o had become. However, the ancients could not explain why a -According times a stayed and times to e or o was. Already Franz Bopp , the founder of the Indo-European, had in vain for conditions for which different development from the supposed origin vowel a sought ( "without any proof laws for each repeated choice of these three vowels indicate left"). For the young grammarians it followed from the postulate of invariability that it was not Sanskrit that had received the old vowels best, but that the European languages and that a , e and o had merged into an a- sound in Sanskrit .
- Hadumod Bußmann (Ed.): Lexicon of Linguistics. 3rd, updated and expanded edition. Kröner, Stuttgart 2002, ISBN 3-520-45203-0 .
- Harald Wiese: A journey through time to the origins of our language. How Indo-European Studies explains our words. Logos Verlag, Berlin 2007, ISBN 978-3-8325-1601-7 .
- Gerhard Jäger : How bioinformatics helps to reconstruct the history of language. T übingen 24 November 2011 (  on www.sfs.uni-tuebingen.de), here p 12 f.