How many vowels and how many consonants did the Proto-Indo-European Language have?

Question

I am interested in development paths of Russian and English sound systems.

At present the situation is as follows: according to WALS, the consonant inventory of modern Russian is classed as "moderately large", while that of Modern English is considered "average". Russian palatalization has a lot to do with it but not only. There is an even bigger difference in vowel inventories (5/6 Rus.: about 21 Engl.), though WALS does not consider vowel lengths and diphthongs as the study is based on vowel qualities.

I am trying to go back to the start (i.e. to PIE) and pinpoint when and how (or possibly why) these differences occurred. Following my research I have already established that Proto-Germanic (which later evolved into Old English) is thought to have had nearly twice as many vowels as Proto-Slavic (which eventually gave life to Old Russian) but that number still is nearly a half of what Modern English has (if one counts diphthongs and trip thongs).

At the moment I am trying to find out how many vowels and consonants PIE language is thought to have had. PIE is not my specialism and I feel a bit lost as there are different opinions of various linguistic schools as well as a considerable number of small nuances. What I am trying to get is a very general idea of PIE sound inventory, sort of PIE phonology in a nutshell. I appreciate that PIE is a re-constructed language and different linguist proposed different theories about how it worked but has anybody ever come out with an approximate number for its possible vowels and consonants?

Thank you.

Answer 1

I am answering the part of your question referring to vowels.

Reconstructed Indo-European is essentially a set of quasi-algebraic symbols for the purpose of establishing regular sound correspondences between the attested languages. No one knows how proto-Indo-European was actually pronounced. The currently fashionable doctrine is that PIE had only two real vowels, namely /e/ and /o/. The vowels /i/ and /u/ are explained as syllabic variants of the semivowels, and the long vowels and /a/ are explained as the result of laryngeals. But this means only that to account for the forms occurring in the attested languages the assumption of two vowels is sufficient. This does not necessarily have any consequences for the real pronunciation of PIE.

Answer 2

As for the vowels. There are couple of approaches. The reductionist approach (embraced for example by the Leiden school) curtails the reconstruction to just 2 phonological vowels, /e/ and /o/, alternating in morphonological system called ablaut. The remaining vowels that can be reconstructed on the basis of daughter languages data, that is low central /a/, two high /i/ and /u/ and long variants of all these are assumed to develop by changes connected with syllabicity of glides /y/ and /w/ and loss of laryngeals. On the other hand the American tradition for example assumes a full system of /i, e, a, o, u/ with long /e,o/ variants. If one would have to derive a consensus concerning the IE vowel system: it is commonly accepted that /i/ and /u/ emerged from syllabic allophones of glides /y/ and /w/. Majority of scholars also accepts the notion of lengthened vowels developing from various compensatory lengthening-like changes. Reconstruction of true vowel /a/ remains the biggest point of dispute. Leiden tries to explain every evidence for it using laryngeal coloring of /e/ whilst the Americans accept it as it is.

These debates however mostly regard to reconstruction of very early PIE system (especially the reductionist approach). The late PIE vowel system, after the laryngeal coloring and loss and the phonologization of syllabic high vowels would consist of approximately 7-9 vowels, depending on the number of lengthened vowels one would reconstruct.

The view of consonant system is far more clear, with minor variations among scholars, usually concerning the phonetic character of certain phonemes, not the whole structure of phonological system.

Five sets of stops are reconstructed, each with a voiceless, voiced and breathy voiced variant: labial, dental, palatovelar, velar and labiovelar. There is one dental sybilant /s/, three laryngeals, two glides /y,w/, two nasals /m,n/ and two resonants /r,l/. All in all it gives a total system of 25 consonant phonemes.