Carpathian historical development

Carpathian is descended from Proto-Indo-European. This language in turn is the parent language of the vast majority of European languages (including English, German, Spanish, French, etc). Proto-Carpathian gradually evolved into various modern Carpathian dialects during the first millennium CE, concurrent with the Slavic, Avar and Hungarian contact. There is no scholarly consensus concerning either the number of stages involved in the development of the language and their periodisation, but for convenience, three stages are usually defined as follows:

Proto-Carpathian (3500 BCE — 1000 BCE) — a long period of gradual development from Proto-Indo-European. No dialectal distinctions can be reconstructed from this period. Loanwords from an unknown, likely pre-Indo-European substratum entered the language.
Common Carpathian (1000 BCE — 500 CE) — the stage with the earliest identifiable dialectal distinctions and borrowings from other languages. At this stage Paleo-Balkan influence is prominent.
Late Carpathian (500 BCE — present) — gradual development of individual Carpathian dialects. The influence of the Slavic languages is prominent at this stage.

Split from Late Proto-Indo-European

Proto-Carpathian exhibits the satem development wherein Proto-Indo-European (PIE) palatovelar consonants became affricates or fricatives, conventionally indicated as *ś and *ź.

*ḱ → *ś
*ǵ, *ǵʰ → *ź

These later became retroflex fricatives *š and *ž in the Western dialects, but dental fricatives *s and *z in the Eastern dialects, which is the feature that defines each group (and became the main difference for the subsequent Western and Eastern standard languages).

This sound change was incomplete, in that the Carpathian languages has instances where PIE palatovelars appear as *k and *g, such as kalaušētei “to be listening” from *ḱléwseti, gansis “goose” from *ǵʰh₂éns. Some of these instances are explained by prohibitive dissimilation: *Ḱ_s > K_s — when a palatovelar is next to a sibilant within the same root, it loses its palatalisation (this, however, does not explain words such as hakmū “stone” from *h₂éḱmō. According to Matasović, the depalatalisation of palatovelars also occurred before sonorant followed by a back vowel: *Ḱ_RV_back > K/_RV_back).

Other satem sound changes are the unconditional delabialisation of labiovelar consonants (*Kʷ > K) and the ruki sound law (*{r,u,k,i}s > {r,u,k,i}š), according to which the dental sibilant *s became retroflex *š after *r, *u, *k or *i. In Eastern Carpathian this new š reverted back to s before plosive consonants (in some southern dialects before all consonants), but was retained in other positions, being the only source of the retroflex sibilant in these dialects. In Western Carpathian, on the other hand, *ś and š merged with very few exceptions, such as tor̃sā “bristle” corresponding to Eastern tar̃šā “crumb”.

The final consonants, except for *n and *s were lost. Final *m changed to n. Final resonants were preserved by addition of a new ending: PIE *péh₂wr̥ “wheat” > *púhr-an > Car. pūrha “bromegrass”. Final plosives were dropped: PIE *tod > Car. ta “it”.

PIE voiced aspirated consonants merged with their plain counterparts:

*bʰ → *b
*dʰ → *d
*gʰ → *g

However, the distinction between the two series manifested as Winter's law, which operated before plain voiced stops, giving the syllable rising acute accent and lengthening the vowel (with some exceptions, such as stògas “stack” from PIE *stógos.

The short vowels *o and *a merge early in Proto-Carpathian resulting in the back likely labialised vowel *a, which was preserved unchanged in Eastern Carpathian. This is supported by later loanwords, such as hamaras “sombre, gloomy” likely from Avar homor (however, Eastern dial. humuras also exists, suggesting that *a was an open vowel with weak labialisation. The borrowing from Proto-Slavic *xmura “cloud” is possible). In most Western dialects new short o arose from *a under certain conditions, such as under circumflex accent in a closed syllable, or near labial consonants: gor̃šatas “earthquake”,wongìs “fire”. Some a>o changes are irregular, likely of an affective nature: dòštei “to resemble” (Eastern: dasētei).

The PIE diphthong *ew became *jau after consonants (*au before labials and h) and *aw after vowels: háugetei “to grow” from PIE *h₂ewgeti, liaũbas “sweet” from *léwbʰos.

Syllabic sonorants become liquid diphthongs with *i (sometimes *u) inserted before them. *u instead of *i is expected before labiovelars, which means that the change happened before the delabialisation of velars. Another change that happened during the same period was *wl, *wr > *l, *r word-initially (but *wrōdnas > W. wōrdanas, E. wōrdaras “dawn” (cognate with Sl. *rànъ “morning”), which preserves the initial *w through vowel metathesis, however the reconstruction *wōrdnas is also possible, likely related to war̃dinas “early”).