Are consonant mutations in Indo-European languages specific of the Celtic group?

Question

Consonant mutations are a strong characteristic of the Celtic languages. An example in Breton would be:

Khaz /kaz/: cat
Ar c'haz /aʁ.xaz/: the cat

The /k/ is altered to /x/ after ar.

According to Wikipedia there are mutations in Russian, but I am not familiar with the process. Are these similar to the Celtic mutations or a completely different thing? Where do the Celtic ones come from? Is it a peculiarity of Celtic languages, or could it be traced back in others, maybe ancient, Indo-European groups?

Answer 1

Something similar shows up in some of the Italian dialects. The relevant dialects are the ones with the following two features:

1) The Gorgia Toscana: After a vowel, p, t and k go to [ɸ], [θ] and [h]. This happens even when the triggering vowel is in the preceding word: la casa is [la'hasa] in dialects with this feature. But it only affects single p, t and k, not the geminate consonants pp, tt and kk.

2) Syntactic doubling: There are some specific words that, idiosyncratically, trigger gemination on the first consonant of the following word. This has the effect of blocking the preceding sound change. So a casa is [ak'kasa], and not [a'hasa].

If a Celticist were describing this sort of Italian they might say it had two mutation classes. Some words trigger "lenition" or "spirant mutation," others trigger "hard mutation."

If I understand correctly, there are even minimal pairs of words that only differ in which mutation they cause. So for instance, the clitic pronoun si doesn't trigger fortition, but the particle sì, meaning "if," does. This is a little like how, in Irish, a means "his" if it's followed by lenition, and "hers" if it isn't. The Italian examples are not as dramatic as the Irish ones, though — my perception is that there are a lot fewer minimal pairs like this in Italian.

Answer 2

Wikipedia, quoting Temes, Elmar, 1986, writes:

Historically, the Celtic initial mutations originated from progressive assimilation and sandhi phenomena between adjacent words. For example, the mutating effect of the conjunction a 'and' is due to the fact that it used to have the form *ak, and the final consonant influenced the following sounds

There are sandhi and sandhi-like phenomena in other IE languages (French for example), and this specific consonant mutation in celtic languages (which is called lenition) can be found in other IE languages. However, there are multiple types of lenition:

• diachronic - a lenition that has happened historically - a consonant was strong in Latin, but has weakened in Italian, for example
• synchronic - the change happens in the present form of a single language. Such, according to Wikipedia, happens in Western Romance languages in addition to Celtic languages, although it does not bear grammatical meaning as in Celtic ones.

Answer 3

A similar phenomenon to Irish eclipsis exists in Modern Greek, although more limited in terms of the number of consonants it applies to. According to Wikipedia's article on "Modern Greek Phonology":

[when a word beginning with a voiceless stop follows] a number of grammatical words ending in /n/, most notably the negation particles δεν and μην and the accusative forms of the personal pronoun and definite article τον and την [..] /n/ either assimilates for place of articulation to the stop, or is altogether deleted, and the stop becomes voiced. This results in pronunciations such as τον πατέρα [to(m)baˈtera] ('the father') or δεν πειράζει [ðe(m)biˈrazi] ('it doesn't matter'), instead of *[ton paˈtera] and *[ðen piˈrazi]. The precise extent of assimilation may vary according to dialect, speed and formality of speech.

Answer 4

There are consonant alternations in Russian but they work in a somewhat different way than in Celtic, and therefore I'm not sure that it's a good idea to call them the same name, mutation. In short and off the top of my head,

1. Celtic mutations happen in anlaut and are petrified sandhi phenomena which may, at least in some cases, be the only carriers of morphological information nowadays (see the use of the Irish article an).

2. Russian (Slavonic) alternations happen on morpheme boundaries, are a by-product of regular sound changes and can't carry morphological information on their own. Examples from Polish:

   kot 'cat' + -e praep., voc. > koci.e [koće], e.g. in *o kocie* '1. about a cat; 2. oh [my] cat!'
   krok 'step' + -ek dimin. > krocz.ek [kroček] 'a small step'
   mnich 'monk' + -i pl. > mnisi [mńiśi] 'monks'
   rzek.a 'river' + -e praep. > rzec.e [žece], e.g. in *w rzece* 'in the river*
   wag.a 'scales' + -e praep. > wadz.e [vaʒe], e.g. in *na wadze* 'on the scales'
   

Answer 5

Hebrew is not strictly Indo-Eurpoean (although some argue it is), but it has something similar: the fricatives /v/, /χ/ and /f/ (when represented by the letters ב, כ and פ) become the plosives /b/, /k/ and /p/ when they come at the start of the word, or after some prepositions, but not after other prepositions. This is called a Dagesh Kal.

For example,

כּלב kelev: dog

הכּלב hakelev: the dog

but,

לכלב leχelev: for/to a dog