Carpathian ablaut

The Carpathian ablaut (from German Ablaut) is a system of apophony. It is a significant and important part of the Carpathian morphology. The ablaut alternations are grouped into three grades: full, zero and lengthened. The full grade is a short vowel or a diphthong, the zero grade is either a short "i" (rarely also "u") or in some cases no vowel at all, and the lengthened grade is a long vowel. Originally, long diphthongs were a part of the lengthened grade as well, but they merged with their short counterparts everywhere, except under stress. The three grades form a quantitative ablaut type. The other type of ablaut is qualitative and arose from the alternation between original *e and *o in the proto-language, both as monophthongs and diphthongs. Most of the reasons from the rise of ablaut were phonetic, rooted in conditions of stress or in certain phonetic environments. These conditions were later eliminated or altered, resulting in a transformation of ablaut into a morphological change. Analogy and sound changes eliminated most of the inflectional ablaut alternations, thereby simplifying the declensional paradigms and limiting ablaut mostly to derivational morphology. In modern Carpathian, unlike its ancestor Proto-Indo-European, ablaut patterns became etymologically opaque, meaning it is no longer possible to distinguish the original root and from its derivatives. Certain words, created in an ablaut pattern, became obsolescent, leaving gaps in the ablaut chain of their roots. For instance: lōpis “petal” and lapastis “blade” represent lengthened and full grades of the o-vowel. The underlying verb with e-vowel is missing. Very few roots create complete chains with many roots never developing them in the first place, while other roots lost some forms and preserved other, that were used more frequently.

Thus, a complete list of ablaut alternation is represented in the table below:

full	zero	lengthened
e	∅, i, u	ē
a		ō
a		ā
ai	i	ī
au	u	ū

Some roots exist as doublets — words with similar or identical meaning but different vowel grade. Various dialects preserve different doublets, many of which have a tendency to appear either in Western or Eastern Carpathian exclusively, for example: Western kalaušas — Eastern kilušas “hearing”, beberas “beaver”, kateras “which”, kerna “shrub” — Eastern kilušas, babaras, kataras, kirna.

The qualitative ablaut

The qualitative form of Carpathian ablaut most commonly presents as e-o-alternations. In Proto-Indo-European it operated in the root, suffixes and theme morphemes, both in inflectional and derivational morphology. In Carpathian, however, the former is reduced to ending alternations: nominative neba — genitive nebesis “sky”, consonant-stem noun. The alternation is present in some derivational suffixes: kateras “which (of two)” — dialectal kataras, although this may be explained by vowel assimilation. In verb roots qualitative ablaut has been preserved in many verbs: neigetei “to need” — naigatas “which is needed”, but such ablaut is no longer productive.

However, qualitative ablaut is still visible and productive in several derivational categories:

Substantives with an "a"-vowel in their roots, derived from verbs without suffixes with an "e"-vowel, denoting action or agent: rektei “to say” — rakas “law”, bergetei “to protect” — bargas “protection”. Some words have undergone semantic drift or became obsolete: garmas “thunder” from dial. germetei “to mutter” (the zero-grade girmētei “to thunder”, derived from the e-grade verb, still exists though); gadas “meeting, gathering” from *gʰedʰ-, though the "e"-grade verb did not survive.
Substantives, ending in -ā, denoting the product of an action, derived from verbs with e-vowel roots: nertei “to plunge” — narā “hole, burrow”; pentei “to stretch” — panā “curtain”; weltei “to allow” — waliā “will, freedom”.
Substantives, ending in -is, denoting agents of action, tools or states: sengetei “to reach” — sangis “that which reaches”. No longer productive.
Progressive or iterative verbs with a-vowel: nestei “bring, carry” — nasītei “to be carrying”; lemtei “to break” — lamītei “to be breaking”.
Causative verbs with a-vowel from adjectives with e-vowel: teišas “still, quiet” — taišītei “to console”.

Zero-grade

In Proto-Indo-European the zero-grade ablaut arose in originally unstressed syllables and was represented by absence of a vowel, or by syllabic sonorants. In Carpathian the old zero-grade was replaced by short "i"- or "u"-vowels, when before a syllabic sonorant. The original zero-grade with no vowel is rare and unproductive in Carpathian, often being altered by later anaptyxis. One example of inflectional zero-ablaut is in the conjugation of the verb dōtei “to give”: dōsti “gives” — dōdinti “they give” (the few examples of a reduplicated stem in Carpathian).

New zero-grade is widely present in verbs:

Infinitives of intensive or progressive verbs: berō “I pick up” — birātei “to pick up”; genō “I drive” — guntei “to drive”; peisiō “I write” — pisātei “to write”.
Detransitive verbs with the ē-suffix: baudītei “to wake” — budētei “to be awake”; swaitātei “to dawn” — switētei “to shine”.
Inchoative verbs from progressive verbs and adjectives: saušas “dry” — sušnetei “to dry up”. Some original inchoative verbs instead have conjugational zero-ablaut: legetei “to lie down” — lingō “I lie down”; rēstei “to find” — rindō “I find” (here the -n-infix does not appear in the infinitive).

Its use in derivation is much less common, than the qualitative ablaut:

samdas “agreement” from dētei “to do”, where the root is reduced to a single consonant "d".

Lengthened grade

Late Proto-Indo-European had two long vowels (*ē and *ō), the sources of which were manifold. In the dialect of disintegrating Proto-Indo-European, which later became Carpathian, the length contrast led to a morphological alternation. The separate lengthened grade existed for both monophthongs and diphthongs, but later in Proto-Carpathian the full grade of diphthongs (*ai and *au) was reanalysed as the addition of *a to a full vowel (*i and *u respectively), which led to the addition of *a to the original *e and *a, which resulted in lengthening of those vowels. The loss of laryngeals further contributed to the establishment of the lengthened grade.

The lengthened grade is present in the inflectional morphology, although no longer productive:

Consonant-stem declension in nouns: nominative pīlēn — genitive pīlentis “chicken”.
Sigmatic aorist of verbs without a thematic vowel: nestei “to carry” — nēsun “I carried”, westei “to lead” — wēsun “I led”.
Prefix and preposition doublets: par(a)- “towards” and parā(h)- “before, proto-”, pa “after” — pā- “later, secondary”, ba “for, because” — bā “indeed, as”.

In derivational morphology, the lengthened grade is scattered and does not form regular patterns the same way, as the full and zero grades do. Some nominal derivation involves root vowel lengthening:

Substantives, ending in -is from verbs with full-grade root vowels, denoting product or result of an action: rektei “to say” — rēkis “speech”, dwestei “to breathe” — dwēstis “living being”, tartei “to speak” — dial. tāris “language”.
Affective nouns from neutral counterparts: žariā “aurora, daybreak” — žōriā “dawn”; gamis “confusion” — gāmas “din”

The legthened grade can be involved in qualitative ablaut in the same way as the full grade, such as to create causative verbs: rēžetei “to cut” — rōžītei “to strike”. The reverse is also possible, such as when forming stative verbs from verbs with long root vowel: stātei “to become” ― stahētei “to stand”.

ū- and ī-grades

Unlike in Proto-Indo-European, in Carpathian u and i were full vowels and took part in quantitative alternations alongside o and e. Resulting mostly from the loss of laryngeals "ū" and "ī" gave rise to a lengthened grade, which later spread by analogy and was employed in several morphological categories:

Forming new intransitive verbs from transitive verbs with full grade vowels: ūktei “to learn”, aukītei “to teach” (full grade), unnautei “to get accustomed” (zero grade).
Deriving substantives from verbs with zero grade: źūka “nickname” from źuhētei “to call”, pilīskas “patter” from piliskātei “to clap, to patter”.
Forming iterative verbs from the non-iterative ones: kalāwītei “to be praising” from kalautei “to be famous”. This type is unproductive and may be a borrowing from the Slavic languages (slaviti from sluti respectively).

ui-grade

The lengthened grade of the u and i vowels arose very early, secured by the loss of laryngeals in that position. The origin of the diphthong ui is more obscure, however. It might have appeared through an analogy with other "i"-type diphthongs ("ai" and "ei") as a full grade of the vowel "u". In the standard "ū" is a lengthened grade and "au" is a full grade instead. A few verbs show this grade in dialects, such as muitei “to wash”, hruitei “to dig” and kiruitei “to cover” (Standard: mautei, hrūtei “to tear out” and karautei respectively).