conlangernoob wrote: ↑Tue Mar 14, 2023 2:53 pm
Four dumb questions: In general, how many sound changes does a language go through every, say, 1,000 years? Also, how much variation is there?
As others have said, it's very variable. However over time it's generally the case that languages generally take 1,000 years to change to a point where they're mutually incomprehensible with the original. How many sound changes this involves depends greatly on the phonology of the language, the speaker base, and how you define one sound change.
Bearing that in mind, I'll give you Spanish as an example. Ralph Penny's
A History of the Spanish Language lists 33 changes over about 2,000 years for Latin to Spanish. However, some of these involve series rather than single phonemes; for example, one of the changes is:
20. Lenition [...]
(a) geminate > simple (and sonorant are additionally modified: LL > /ʎ/, NN > /ɲ/, RR > /r̄/);
(b) voiceless > voiced (e.g. -T- > /d/, -S- > /z/, /ts/ > /dz/);
(c) voiced plosives > fricatives (and are often eliminated)
(d) /j/ > /zero/.
If you wanted to break this up into individual steps, you could think of it as at least half a dozen changes. Penny's list of 33 could easily be expanded to 50 or 100 depending on what you think of as a single change.
Contrast this to Hawaiian for example, where you might only be able to list 10 sound changes for the same depth of time, yet with a similar degree of mutual unintelligibility with its ancestor. Basically, over 1000 years you probably want enough developments to significantly alter the language, but how many changes that actually involves is up to you. Although there are some exceptions like Icelandic where remarkably little has happened. You're pretty safe if you go anywhere between "not very many" and "quite a lot" of sound changes per millenium.
Also, do some types of sound change occur more than others?
Yes. There are some very common sound changes, like intervocalic lenition, palatalisation, cluster simplification, anticlockwise movement of back vowels etc. Other changes like large chain shifts or fortition are pretty rare, and wacky changes like /r/ → /ɡ͡ʟ/ or /j/ → /p/ are extremely rare but still attested. Sound change likelihood depends on the wider phonology of the language, e.g. if a language has four stops MOAs, it's more likely for one of them to do something than if there's only one. And then there's Sprachbundts where language contact makes sound changes areally more common even when they might be pretty rare everywhere else.
Finally, how many years does it take between a sound change to begin and a sound change to finish?
This is a very difficult question to answer - again it depends a lot on prestige levels and tons of other socioeconomic factors. Sound changes can take a while to spread throughout a community; generally starting with women, whose children learn it from them. It can also take effect at different times in different words (although hardcore neogrammarians would hate to admit this). For a single phoneme change (like /ʎ/ > /j/ or something) it might take only a generation, for more complex changes or changes involving intermediate stages it could be several generations before it fully catches on. I'll go back to Spanish for another example - the Old Spanish sibilant shift (basically /dz z ʒ/ > /ts s ʃ/, /ts/ > /tθ/ > /θ/ and /ʃ/ > /x/) took place within a period of 30 years for some speakers, but it wasn't carried out uniformly even in the standard language for a couple centuries and never completely applied in some dialects. Sound changes are always ongoing and there's about three or four generations of people using a language at any given time, so it's basically impossible to qualify when exactly a sound change has "finished".
