Proto-Indo-European nominals
Proto-Indo-European nominals include nouns, adjectives, and pronouns. Their grammatical forms and meanings have been reconstructed by modern linguists, based on similarities found across all Indo-European languages. This article discusses nouns and adjectives; Proto-Indo-European pronouns are treated elsewhere.
The Proto-Indo-European language had eight or nine cases, three numbers and probably originally two genders, with the animate later splitting into the masculine and the feminine.
Nominals fell into multiple different declensions. Most of them had word stems ending in a consonant and exhibited a complex pattern of accent shifts and/or vowel changes among the different cases.
Two declensions ended in a vowel and are called thematic; they were more regular and became more common during the history of PIE and its older daughter languages.
PIE very frequently derived nominals from verbs. Just as English giver and gift are ultimately related to the verb give, déh₃tors and déh₃nom are derived from deh₃-, but the practice was much more common in PIE. For example, pṓds was derived from ped-, and dómh₂s from demh₂-.
Morphology
The basic structure of Proto-Indo-European nouns and adjectives was the same as that of PIE verbs. A lexical word was formed by adding a suffix onto a root to form a stem. The word was then inflected by adding an ending to the stem.The root indicates a basic concept, often a verb, while the stem carries a more specific nominal meaning based on the combination of root and suffix. Some stems cannot clearly be broken up into root and suffix altogether, as in h₂r̥tḱo-.
The ending carries grammatical information, including case, number, and gender. Gender is an inherent property of a noun but is part of the inflection of an adjective, because it must agree with the gender of the noun it modifies.
Thus, the general morphological form of such words is :
The process of forming a lexical stem from a root is known in general as derivational morphology, while the process of inflecting that stem is known as inflectional morphology. As in other languages, the possible suffixes that can be added to a given root, and the meaning that results, are not entirely predictable, while the process of inflection is largely predictable in both form and meaning.
Originally, extensive ablaut occurred in PIE, in both derivation and inflection and in the root, suffix, and ending. Variation in the position of the accent likewise occurred in both derivation and inflection, and is often considered part of the ablaut system.
For example, the nominative form léymons had the genitive limnés. In this word, the nominative has the ablaut vowels é–o–Ø while the genitive has the ablaut vowels Ø–Ø–é — i.e. all three components have different ablaut vowels, and the stress position has also moved.
A large number of different patterns of ablaut variation existed; speakers had to both learn the ablaut patterns and memorize which pattern went with which word. There was a certain regularity of which patterns occurred with which suffixes and formations, but with many exceptions.
Already by late PIE times, this system was extensively simplified, and daughter languages show a steady trend towards more and more regularization and simplification.
Far more simplification occurred in the late PIE nominal system than in the verbal system, where the original PIE ablaut variations were maintained essentially intact well into the recorded history of conservative daughter languages such as Sanskrit and Ancient Greek, as well as in the Germanic languages.
Root nouns
PIE also had a class of monosyllabic root nouns which lack a suffix, the ending being directly added to the root. These nouns can also be interpreted as having a zero suffix or one without a phonetic body.Verbal stems have corresponding morphological features, the root present and the root aorist.
Complex nominals
Not all nominals fit the basic pattern. Some were formed with additional prefixes. An example is ni-sd-ó-s, derived from the verbal root sed- by adding a local prefix and thus meaning "where sits down" or the like.A special kind of prefixation, called reduplication, uses the first part of the root plus a vowel as a prefix. For example, kʷelh₁- gives kʷe-kʷl-ó-s, and bʰrew- gives bʰé-bʰru-s. This type of derivation is also found in verbs, mainly to form the perfect.
As with PIE verbs, a distinction is made between primary formations, which are words formed directly from a root as described above, and secondary formations, which are formed from existing words.
Athematic and thematic nominals
A fundamental distinction is made between thematic and athematic nominals.The stem of athematic nominals ends in a consonant. They have the original complex system of accent/ablaut alternations described above and are generally held as more archaic.
Thematic nominals, which became more and more common during the times of later PIE and its younger daughter languages, have a stem ending in a thematic vowel, -o- in almost all grammatical cases, sometimes ablauting to -e-. Since all roots end in a consonant, all thematic nominals have suffixes ending in a vowel, and none are root nouns. The accent is fixed on the same syllable throughout the inflection.
From the perspective of the daughter languages, a distinction is often made between vowel stems ā-, and consonantic stems. However, from the PIE perspective, only the thematic stems are truly vocalic. Stems ending in i or u such as men-ti- are consonantic because the i is just the vocalic form of the glide y, the full grade of the suffix being -tey-. Post-PIE ā was actually eh₂ in PIE.
Among the most common athematic stems are root stems, i-stems, u-stems, eh₂-stems, n-stems, nt-stems, r-stems and s-stems. Within each of these, numerous subclasses with their own inflectional peculiarities developed by late PIE times.
Grammatical categories
PIE nouns and adjectives are subject to the system of PIE nominal inflection with eight or nine cases: nominative, accusative, vocative, genitive, dative, instrumental, ablative, locative, and possibly a directive or allative.The so-called strong or direct cases are the nominative and the vocative for all numbers, and the accusative case for singular and dual, and the rest are the weak or oblique cases. This classification is relevant for inflecting the athematic nominals of different accent and ablaut classes.
Number
Three numbers were distinguished: singular, dual and plural. Many athematic neuter nouns had a special collective form instead of the plural, which inflected with singular endings, but with the ending -h₂ in the direct cases, and an amphikinetic accent/ablaut pattern.Gender
Late PIE had three genders, traditionally called masculine, feminine and neuter. Gender or noun class is an inherent property of each noun; all nouns in a language that have grammatical genders are assigned to one of its classes. There was probably originally only an animate versus an inanimate distinction. This view is supported by the existence of certain classes of Latin and Ancient Greek adjectives which inflect only for two sets of endings: one for masculine and feminine, the other for neuter. Further evidence comes from the Anatolian languages such as Hittite which exhibit only the animate and the neuter genders.The feminine ending is thought to have developed from a collective/abstract suffix -h₂ that also gave rise to the neuter collective. The existence of combined collective and abstract grammatical forms can be seen in English words such as youth = "the young people " or "young age ".
Remnants of this period exist in the eh₂-stems, ih₂-stems, uh₂-stems and bare h₂-stems, which are found in daughter languages as ā-, ī-, ū- and a-stems, respectively. They originally were the feminine equivalents of the o-stems, i-stems, u-stems and root nouns. Already by late PIE times, however, this system was breaking down. -eh₂ became generalized as the feminine suffix, and eh₂-stem nouns evolved more and more in the direction of thematic o-stems, with fixed ablaut and accent, increasingly idiosyncratic endings and frequent borrowing of endings from the o-stems. Nonetheless, clear traces of the earlier system are seen especially in Sanskrit, where ī-stems and ū-stems still exist as distinct classes comprising largely feminine nouns. Over time, these stem classes merged with i-stems and u-stems, with frequent crossover of endings.
Grammatical gender correlates only partially with sex, and almost exclusively when it relates to humans and domesticated animals. Even then, those correlations may not be consistent: nouns referring to adult males are usually masculine, nouns referring to adult females are usually feminine, but diminutives may be neuter regardless of referent, as in both Greek and German. Gender may have also had a grammatical function, a change of gender within a sentence signaling the end of a noun phrase and the start of a new one.
An alternative hypothesis to the two-gender view is that Proto-Anatolian inherited a three-gender PIE system, and subsequently Hittite and other Anatolian languages eliminated the feminine by merging it with the masculine.
Case endings
Some endings are difficult to reconstruct and not all authors reconstruct the same sets of endings. For example, the original form of the genitive plural is a particular thorny issue, because different daughter languages appear to reflect different proto-forms. It is variously reconstructed as -ōm, -om, -oHom, and so on. Meanwhile, the dual endings of cases other than the merged nominative/vocative/accusative are often considered impossible to reconstruct because these endings are attested sparsely and diverge radically in different languages.The following shows three modern mainstream reconstructions. Sihler remains closest to the data, often reconstructing multiple forms when daughter languages show divergent outcomes. Ringe is somewhat more speculative, willing to assume analogical changes in some cases to explain divergent outcomes from a single source form. Fortson is between Sihler and Ringe.
The thematic vowel -o- ablauts to -e- in word-final position in the vocative singular, and before h₂. The vocative singular is also the only case for which the thematic nouns show accent retraction, a leftward shift of the accent, denoted by -ĕ.
†The dative, instrumental and ablative plural endings probably contained a bʰ but are of uncertain structure otherwise. They might also have been of post-PIE date.
§For athematic nouns, an endingless locative is reconstructed in addition to the ordinary locative singular in -i. In contrast to the other weak cases, it typically has full or lengthened grade of the stem.
An alternative reconstruction is found in Beekes. This reconstruction does not give separate tables for the thematic and athematic endings, assuming that they were originally the same and only differentiated in daughter languages.