There is a general consensus as to which nominal accent-ablaut patterns must be reconstructed for Proto-Indo-European. Given that the foundations for the system were laid by a group of scholars (
Schindler,
Eichner,
Rix, and
Hoffmann) during the 1964
Erlanger Kolloquium, which discussed the works of
Pedersen and
Kuiper on nominal accent-ablaut patterns in PIE, the system is sometimes referred to as the
Erlangen model.
Early PIE Early PIE nouns had complex patterns of ablaut according to which the root, the stem and the ending all showed ablaut variations. Polysyllabic athematic nominals (type ) exhibit four characteristic patterns, which include accent and ablaut alternations throughout the paradigm between the root, the stem and the ending. •
Acrostatic (< + , "stationary on the beginning"): The accent stays on the root. •
Proterokinetic (< + , "moving towards the earlier [closer to the root]"): The best evidence for the reconstruction of this type comes from , (< ideal ) and , . (< ideal ) in
Ancient Greek and , . (< ) in
Old Irish. •
Hysterokinetic (< , "moving towards the latter [of the syllables following the root]"). •
Amphikinetic (< , "moving towards both sides"). Root nouns (type ) show a similar behavior but with only two patterns. The patterns called "Narten" are, at least formally, analogous to the
Narten presents in verbs, as they alternate between full () and lengthened grades (). Notes: • For the strong cases of proterokinetic nominals, the accent is placed on the penultimate syllable of the stem. If there is only one suffix, the root will be the penultimate syllable; when there is more than one suffix, the penultimate syllable will be a suffix, and the root will appear unaccented and in the zero grade. • There is an unexpected
o-grade of the suffix in the strong cases of polysyllabic amphikinetic nominals. Another unusual property of this class is the locative singular having a stressed
e-grade suffix. The classification of the amphikinetic root nouns is disputed. Since those words have no suffix, they differ from the amphikinetic polysyllables in the strong cases (no
o-grade) and in the locative singular (no
e-grade suffix). Some scholars prefer to call them amphikinetic and the corresponding polysyllables
holokinetic (or
holodynamic, from holos = whole). Some also list
mesostatic (meso = middle) and
teleutostatic types, with the accent fixed on the suffix and the ending, respectively, but their existence in PIE is disputed. The classes can then be grouped into three
static (acrostatic, mesostatic, teleutostatic) and three or four
mobile (proterokinetic, hysterokinetic, amphikinetic, holokinetic) paradigms.
"Late PIE" By late PIE, the above system had been already significantly eroded, with one of the root ablaut grades tending to be extended throughout the paradigm. The erosion is much more extensive in all the daughter languages, with only the oldest stages of most languages showing any root ablaut and typically only in a small number of irregular nouns: •
Vedic Sanskrit: , < PIE , • , . < PIE , •
Old Avestan: , . < PIE , •
Ancient Greek: , . ,
Vedic Sanskrit: , . , both < PIE , 'sky, day, god' •
Proto-Germanic: reconstructed , . < PIE , , with the nominative stem preserved in , , , and the genitive stem in . The most extensive remains are in Vedic Sanskrit and Old Avestan (the oldest recorded stages of the oldest Indic and Iranian languages, ); the younger stages of the same languages already show extensive regularization. In many cases, a former ablauting paradigm was generalized in the daughter languages but in different ways in each language. For example, Ancient Greek < PIE nominative and < PIE genitive reflect different stems of a PIE ablauting paradigm , , which is still reflected directly in Vedic Sanskrit .
dā́ru 'wood', .
drṓs. Similarly, PIE , can be reconstructed for 'knee' from Ancient Greek and Old English
cnēo. In that case, there is no extant ablauting paradigm in a single language, but Avestan accusative and
Modern Persian are attested, which strongly implies that
Proto-Iranian had an ablauting paradigm. That is quite possible for Avestan as well, but that cannot be certain since the nominative is not extant. An ablauting paradigm , can also clearly be reconstructed from 'foot', based on Greek: . (< , ) vs. . (< ) vs. (< ), with differing ablaut grades among cognate forms in different languages. In some cases, ablaut would be expected based on the form (given numerous other examples of ablauting nouns of the same form), but a single ablaut variant is found throughout the paradigm. In such cases, it is often assumed that the noun had shown ablaut in early PIE, but was generalized to a single form by late PIE or shortly afterwards. An example is Greek , Sanskrit , Latin , Gothic . All except the Latin form suggest a masculine
u-stem with non-ablauting PIE root , but certain irregularities (the position of the accent, the unexpected feminine
ā-stem form in Latin, the unexpected Gothic stem <
ǵenw-, the ablaut found in Greek < PIE , < ) suggest an original ablauting neuter noun , in early PIE. It generalized the nominative ablaut in late PIE and switched to the masculine
u-stem in the post-PIE period. Another example is ; an acrostatic root paradigm might be expected based on the form, but the consistent stem is found throughout the family. With the discovery of
Hittite, however, the form
wikt:𒉈𒆪𒊻| < was found, which is evidently a genitive; it indicates that early PIE actually had an acrostatic paradigm that was regularized by late PIE but after the separation of Hittite.
Leiden model Kuiper's student
Beekes, together with his colleague
Kortlandt, developed an alternative model on the basis of Pedersen's and Kuiper's works, described in detail in . Since the scholars who developed it and generally accept it are mostly from the
University of Leiden, it is generally dubbed the
Leiden model. It states that for earlier PIE, three accent types of inflection of consonant stems are to be reconstructed, and from them, all of the attested types can be derived: For root nouns, accentuation could have been either static or mobile: The thematic stem type was a late innovation, with a thematic vowel originating from the hysterodynamic genitive singular form of athematic inflection, which had in pre-PIE the function of
ergative. That is why there are
o-stems but no
e-stems and is suggested to be why thematic nouns show no ablaut or accentual mobility in inflection (for other theories on the origin of thematic vowel see
Thematic vowel: Origin in nouns). The general points of departure to the Erlangen model are: • Both models share (acro)static and
proterodynamic patterns. • The
hysterokinetic and
amphikinetic patterns are reconstructed only in the Erlangen model. • The
hysterodynamic model exists only in the Leiden model and represents an earlier stage of the hysterokinetic and amphikinetic patterns of the Erlangen model. The reconstruction of the paradigm is not based only on
internal reconstruction. It is synchronically still attested in the Hittite paradigm of the word for "hand": , , . That is therefore one of the most archaic paradigms in PIE. • The Leiden model describes a stage, Early PIE, that is relatively older than the Erlangen model. • The Leiden model has a one-to-one correlation between the presence of the full grade vowel and the position of the
accent, which indicates a historical connection between the two. At the stage of the Leiden model, there was only one phonemic vowel, as was always accented, and the new vowel, , was always unaccented. Both were therefore in
complementary distribution. ==Heteroclitic stems==