Domestication of the horse
Nordic Bronze Age
Painted Grey Ware
Northern Black Polished Ware
Peoples and societies
Religion and mythology
Copenhagen Studies in Indo-European
Encyclopedia of Indo-European Culture
The Horse, the Wheel and Language
Journal of Indo-European Studies
Indogermanisches etymologisches Wörterbuch
Indo-European Etymological Dictionary
This article contains characters used to write reconstructed
Proto-Indo-European words. Without proper rendering support, you may
see question marks, boxes, or other symbols instead of Unicode
combining characters and
Proto-Indo-European (PIE) is the linguistic reconstruction of the
hypothetical common ancestor of the Indo-European languages, the most
widely spoken language family in the world.
Far more work has gone into reconstructing PIE than any other
proto-language, and it is by far the best understood of all
proto-languages of its age. The vast majority of linguistic work
during the 19th century was devoted to the reconstruction of PIE or
its daughter proto-languages (e.g. Proto-Germanic), and most of the
modern techniques of linguistic reconstruction such as the comparative
method were developed as a result. These methods supply all current
knowledge concerning PIE since there is no written record of the
PIE is estimated to have been spoken as a single language from 4,500
B.C.E. to 2,500 B.C.E. during the
Neolithic Age, though estimates
vary by more than a thousand years. According to the prevailing Kurgan
hypothesis, the original homeland of the
Proto-Indo-Europeans may have
been in the
Pontic–Caspian steppe of Eastern Europe. The linguistic
reconstruction of PIE has also provided insight into the culture and
religion of its speakers.
Proto-Indo-Europeans became isolated from each other through the
Indo-European migrations, dialects of the Proto-Indo-European language
spoken by the various groups underwent the Indo-European sound laws
divergence, and along with shifts in morphology, they slowly but
eventually transformed into the known ancient Indo-European languages.
From there, further linguistic divergence lead to the evolution of
their current descendants, the modern Indo-European languages. Today,
the most widely-spoken descendant languages, or daughter languages, of
PIE are Spanish, English, Hindustani (
Hindi and Urdu), Portuguese,
Bengali, Russian, Punjabi, German, Persian, French, Italian and
Marathi. Hundreds of other living descendant languages of PIE range
from languages as diverse as Albanian (gjuha shqipe), Kurdish
(کوردی), Nepali (खस भाषा), Tsakonian
(τσακώνικα), Ukrainian (українська мова), to
PIE had an elaborate system of morphology that included inflectional
suffixes (analogous to English life, lives, life's, lives') as well as
ablaut (vowel alterations, for example, as preserved in English sing,
sang, sung) and accent. PIE nominals and pronouns had a complex system
of declension, and verbs similarly had a complex system of
conjugation. The PIE phonology, particles, numerals, and copula are
An asterisk is used to mark reconstructed words, such as *wódr̥
'water', *ḱwṓ 'dog' (English hound), or *tréyes 'three
1 Development of the hypothesis
2 Historical and geographical setting
3 Subfamilies (clades)
3.1 Subfamily clades
3.2 Marginally attested languages
7 Relationships to other language families
8 In popular culture
9 See also
11 Further reading
12 External links
Development of the hypothesis
No direct evidence of PIE remains – scholars have reconstructed PIE
from its present-day descendants using the comparative method.
The comparative method follows the
Neogrammarian rule: the
Indo-European sound laws
Indo-European sound laws apply without exception. The method compares
languages and uses the sound laws to find a common ancestor. For
example, compare the pairs of words in Italian and English: piede and
foot, padre and father, pesce and fish. Since there is a consistent
correspondence of the initial consonants that emerges far too
frequently to be coincidental, one can assume that these languages
stem from a common parent-language.
Many consider William Jones, an
Anglo-Welsh philologist and puisne
judge in Bengal, to have begun
Indo-European studies in 1786, when he
postulated the common ancestry of Sanskrit, Latin, and Greek.
However, he was not the first to make this observation. In the 1500s,
European visitors to the Indian subcontinent became aware of
Indo-Iranian languages and European languages,
and as early as 1653
Marcus Zuerius van Boxhorn
Marcus Zuerius van Boxhorn had published a
proposal for a proto-language ("Scythian") for the following language
families: Germanic, Romance, Greek, Baltic, Slavic, Celtic, and
Iranian. In a memoir sent to the Académie des Inscriptions et
Belles-Lettres in 1767 Gaston-Laurent Coeurdoux, a French Jesuit who
spent all his life in India, had specifically demonstrated the analogy
Sanskrit and European languages. In some ways, Jones' work
was less accurate than his predecessors', as he erroneously included
Egyptian, Japanese and Chinese in the Indo-European languages, while
Rasmus Christian Rask
Rasmus Christian Rask elaborated the set of correspondences to
include other Indo-European languages, such as
Sanskrit and Greek, and
the full range of consonants involved. In 1816
Franz Bopp published On
the System of Conjugation in
Sanskrit in which he investigated a
common origin of Sanskrit, Persian, Greek, Latin, and German. In 1833
he began publishing the Comparative Grammar of Sanskrit, Zend, Greek,
Latin, Lithuanian, Old Slavic, Gothic, and German.
Jacob Grimm formulated what became known as
Grimm's law as a
general rule in his Deutsche Grammatik. Grimm showed correlations
between the Germanic and other
Indo-European languages and
demonstrated that sound change systematically transforms all words of
a language. From the 1870s the Neogrammarians proposed that sound
laws have no exceptions, as shown in Verner's law, published in 1876,
which resolved apparent exceptions to
Grimm's law by exploring the
role that accent (stress) had played in language change.
August Schleicher's A Compendium of the Comparative Grammar of the
Indo-European, Sanskrit, Greek and
Latin Languages (1874–77)
represented an early attempt to reconstruct the proto-Indo-European
By the early 1900s Indo-Europeanists had developed well-defined
descriptions of PIE which scholars still accept today. Later, the
discovery of the Anatolian and
Tocharian languages added to the corpus
of descendant languages. A new principle won wide acceptance in the
laryngeal theory, which explained irregularities in the linguistic
Proto-Indo-European phonology as the effects of
hypothetical sounds which had disappeared from all documented
languages, but which were later observed in excavated cuneiform
tablets in Anatolian.
Julius Pokorny's Indogermanisches etymologisches Wörterbuch
("Indo-European Etymological Dictionary", 1959) gave a detailed,
though conservative, overview of the lexical knowledge then
accumulated. Kuryłowicz's 1956 Apophonie gave a better understanding
of Indo-European ablaut. From the 1960s, knowledge of Anatolian became
robust enough to establish its relationship to PIE.
Classification of Indo-European languages. Red: Extinct languages.
White: categories or unattested proto-languages. Left half: centum
languages; right half: satem languages
Historical and geographical setting
Multiple hypotheses have been suggested about when, where, and by whom
PIE was spoken. The
Kurgan hypothesis, first put forward by Marija
Gimbutas, is the most popular of these. It proposes that
Kurgans from the
Pontic–Caspian steppe north of the Black Sea were
the original speakers of PIE.
According to the theory, PIE became widespread because its speakers,
the Kurgans, were able to migrate into a vast area of Europe and Asia,
thanks to technologies such as the domestication of the horse,
herding, and the use of wheeled vehicles.
The people of these cultures were nomadic pastoralists, who, according
to the model, by the early 3rd millennium BC had expanded throughout
the Pontic-Caspian steppe and into Eastern Europe.
Other theories include the Anatolian hypothesis, the Armenia
hypothesis, the Paleolithic Continuity Theory, and the indigenous
Aryans theory.
Due to early language contact, there are some lexical similarities
between the Proto-Kartvelian and Proto-Indo-European languages.
An overview map summarizes theories presented above. 
The following are listed by their theoretical glottochronological
All now extinct, the best attested being the Hittite language.
An extinct branch known from manuscripts dating from the 6th to the
8th century AD, which were found in north-west China.
This included many languages, but only descendants of
Portuguese and Galician, Spanish, Catalan, French, Italian, Romanian,
Aromanian, Rhaeto-Romance, Gallo-Italic
The ancestor of modern Celtic languages. Once spoken across Europe,
but now mostly confined to its northwestern edge.
Irish, Scottish Gaelic, Welsh, Breton, Cornish, Manx
The reconstructed proto-language of the Germanic languages. It
developed into three branches: West Germanic, East Germanic (now
extinct), and North Germanic.
English, German, Afrikaans, Dutch, Norwegian, Danish, Swedish,
Frisian, Icelandic, Faroese
Branched into the
Baltic languages and the Slavic languages.
Baltic Latvian and Lithuanian; Slavic Russian, Ukrainian, Belarussian,
Polish, Czech, Slovak, Serbo-Croatian, Bulgarian, Slovenian,
Branched into the Indo-Aryan, Iranian and Nuristani languages.
Nuristani; Indic Hindustani, Bengali, Sinhala, Punjabi, Dardic; Iranic
Persian, Pashto, Balochi, Kurdish, Zaza
Eastern Armenian, Western Armenian
Modern Greek, Romeyka, Tsakonian
Albanian is the only modern representative of a distinct branch of the
Indo-European language family.
Other possible groupings include Italo-Celtic, Graeco-Aryan,
Graeco-Armenian, Graeco-Phrygian, Daco-Thracian, and Thraco-Illyrian.
Marginally attested languages
Lusitanian language is a marginally attested language found in the
area of modern Portugal.
The Paleo-Balkan languages, which occur in or near the Balkan
peninsula, do not appear to be members of any of the subfamilies of
PIE but are so poorly attested that proper classification of them is
Main article: Proto-Indo-European phonology
Proto-Indo-European phonology has been reconstructed in some detail.
Notable features of the most widely accepted (but not uncontroversial)
three series of stop consonants reconstructed as voiceless, voiced,
and breathy voiced;
sonorant consonants that could be used syllablically;
three so-called laryngeal consonants, whose exact pronunciation is not
well-established but which are believed to have existed in part based
on their visible effects on adjacent sounds;
the fricative /s/; and
a five-vowel system of which /e/ and /o/ were the most frequently
Proto-Indo-European accent is reconstructed today as having had
variable lexical stress, which could appear on any syllable and whose
position often varied among different members of a paradigm (e.g.
between singular and plural of a verbal paradigm). Stressed syllables
received a higher pitch; therefore it is often said that PIE had pitch
accent. The location of the stress is associated with ablaut
variations, especially between normal-grade vowels (/e/ and /o/) and
zero-grade (i.e. lack of a vowel), but not entirely predictable from
The accent is best preserved in Vedic
Sanskrit and (in the case of
nouns) Ancient Greek, and indirectly attested in a number of phenomena
in other IE languages. To account for mismatches between the accent of
Sanskrit and Ancient Greek, as well as a few other phenomena, a
few historical linguists prefer to reconstruct PIE as a tone language
where each morpheme had an inherent tone; the sequence of tones in a
word then evolved, according to that hypothesis, into the placement of
lexical stress in different ways in different IE branches.[citation
Proto-Indo-European roots were affix-lacking morphemes which carried
the core lexical meaning of a word and were used to derive related
words (e.g., "-friend-" in the English words "befriend", "friends",
and "friend" by itself). Proto-Indo-European was a fusional language,
in which inflectional morphemes signalled the grammatical
relationships between words. This dependence on inflectional morphemes
means that roots in PIE, unlike those found in English, were rarely
found by themselves. A root plus a suffix formed a word stem, and a
word stem plus a desinence (usually an ending) formed a word.
Many morphemes in Proto-Indo-European had short e as their inherent
Indo-European ablaut is the change of this short e to short
o, long e (ē), long o (ō), or no vowel. This variation in vowels
occurred both within inflectional morphology (e.g., different
grammatical forms of a noun or verb may have different vowels) and
derivational morphology (e.g., a verb and an associated abstract
verbal noun may have different vowels).
Categories that PIE distinguished through ablaut were often also
identifiable by contrasting endings, but the loss of these endings in
Indo-European languages has led them to use ablaut alone to
identify grammatical categories, as in the
Modern English words sing,
Proto-Indo-European nouns are declined for eight or nine cases:
nominative: marks the subject of a verb, such as They in They ate.
Words that follow a linking verb and rename the subject of that verb
also use the nominative case. Thus, both They and linguists are in the
nominative case in They are linguists. The nominative is the
dictionary form of the noun.
accusative: used for the direct object of a transitive verb.
genitive: marks a noun as modifying another noun.
dative: used to indicate the indirect object of a transitive verb,
such as Jacob in Maria gave Jacob a drink.
instrumental: marks the instrument or means by, or with which, the
subject achieves or accomplishes an action. It may be either a
physical object or an abstract concept.
ablative: used to express motion away from something.
locative: corresponds vaguely to the English prepositions in, on, at,
vocative: used for a word that identifies an addressee. A vocative
expression is one of direct address where the identity of the party
spoken to is set forth expressly within a sentence. For example, in
the sentence, "I don't know, John", John is a vocative expression that
indicates the party being addressed.
allative: used as a type of locative case that expresses movement
towards something. Only the
Anatolian languages maintain this case,
and it may not have existed in Proto-Indo-European at all.
There were three grammatical genders:
Proto-Indo-European pronouns are difficult to reconstruct, owing to
their variety in later languages. PIE had personal pronouns in the
first and second grammatical person, but not the third person, where
demonstrative pronouns were used instead. The personal pronouns had
their own unique forms and endings, and some had two distinct stems;
this is most obvious in the first person singular where the two stems
are still preserved in English I and me. There were also two varieties
for the accusative, genitive and dative cases, a stressed and an
Proto-Indo-European verbs, like the nouns, exhibited a system of
ablaut. The most basic categorization for the Indo-European verb was
grammatical aspect. Verbs were classed as:
stative: verbs that depict a state of being
imperfective: verbs depicting ongoing, habitual or repeated action
perfective: verbs depicting a completed action or actions viewed as an
Verbs have at least four grammatical moods:
indicative: indicates that something is a statement of fact; in other
words, to express what the speaker considers to be a known state of
affairs, as in declarative sentences.
imperative: forms commands or requests, including the giving of
prohibition or permission, or any other kind of advice or exhortation.
subjunctive: used to express various states of unreality such as wish,
emotion, possibility, judgment, opinion, obligation, or action that
has not yet occurred
optative: indicates a wish or hope. It is similar to the cohortative
mood and is closely related to the subjunctive mood.
Verbs had two grammatical voices:
active: used in a clause whose subject expresses the main verb's
mediopassive: for the middle voice and the passive voice.
Verbs had three grammatical persons: (first, second and third)
Verbs had three grammatical numbers:
dual: referring to precisely two of the entities (objects or persons)
identified by the noun or pronoun.
plural: a number other than singular or dual.
Verbs were also marked by a highly developed system of participles,
one for each combination of tense and voice, and an assorted array of
verbal nouns and adjectival formations.
The following table shows a possible reconstruction of the PIE verb
endings from Sihler, which largely represents the current consensus
Proto-Indo-European numerals are generally reconstructed as follows:
*trei- (full grade), *tri- (zero grade)
*kʷetwor- (o-grade), *kʷetur- (zero grade)
(see also the kʷetwóres rule)
*s(w)eḱs; originally perhaps *weḱs
*oḱtō, *oḱtou or *h₃eḱtō, *h₃eḱtou
Rather than specifically 100, *ḱm̥tóm may originally have meant "a
Proto-Indo-European particles could be used both as adverbs and
postpositions, like *upo "under, below". The postpositions became
prepositions in most daughter languages. Other reconstructible
particles include negators (*ne, *mē), conjunctions (*kʷe "and",
*wē "or" and others) and an interjection (*wai!, an expression of woe
The syntax of the older
Indo-European languages has been studied in
earnest since at least the late nineteenth century, by such scholars
Hermann Hirt and Berthold Delbrück. In the second half of the
twentieth century, interest in the topic increased and led to
reconstructions of Proto-Indo-European syntax.
Since all the early attested IE languages were inflectional, PIE is
thought to have relied primarily on morphological markers, rather than
word order, to signal syntactic relationships within sentences.
Still, a default (unmarked) word order is thought to have existed in
PIE. This was reconstructed by
Jacob Wackernagel as being
subject–verb–object (SVO), based on evidence in Vedic Sanskrit,
and the SVO hypothesis still has some adherents, but as of
2015[update] the "broad consensus" among PIE scholars is that PIE
would have been a subject–object–verb (SOV) language.
The SOV default word order with other orders used to express emphasis
(e.g., verb–subject–object to emphasise the verb) is attested in
Old Indic, Old Iranian, Old
Latin and Hittite, while traces of it can
be found in the enclitic personal pronouns of the Tocharian
languages. A shift from OV to VO order is posited to have occurred
in late PIE since many of the descendant languages have this order:
modern Greek, Romance and Albanian prefer SVO,
Insular Celtic has VSO
as the default order, and even the
Anatolian languages show some signs
of this word order shift. The inconsistent order preference in
Baltic, Slavic and Germanic can be attributed to contact with outside
Relationships to other language families
Many hypothesised higher-level relationships between
Proto-Indo-European and other language families have been proposed,
but these are highly controversial. Among them:
An Indo-Uralic family, encompassing PIE and Uralic languages.
Eurasiatic languages, which proposes a link of Indo-European and
Altaic languages and the other language families of
Proto-Human language family linking all the languages together.
Pontic languages which proposes an association of Indo-European
with the North-west Caucasian languages.
In popular culture
Ridley Scott film Prometheus features an android named "David"
(played by Michael Fassbender) who learns Proto-Indo-European to
communicate with the "Engineer", an extraterrestrial whose race may
have created humans. David practices PIE by reciting Schleicher's
fable and goes on to attempt communication with the Engineer
through PIE. Linguist Dr Anil Biltoo created the film's reconstructed
dialogue and had an onscreen role teaching David Schleicher's
List of Indo-European languages
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^ Gray, Russell D; Atkinson, Quentin D (27 November 2003),
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^ Roush, George (20 June 2012). "'Prometheus' Secret Revealed: What
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Mallory, JP; Adams, DQ (2006), The Oxford Introduction to
Proto-Indo-European and the Proto-Indo-European World, Oxford: Oxford
University Press, ISBN 9780199296682
Meier-Brügger, Michael (2003), Indo-European Linguistics, New York:
de Gruyter, ISBN 3-11-017433-2
Szemerényi, Oswald (1996), Introduction to Indo-European Linguistics,
Look up Appendix:List of Proto-Indo-European roots in Wiktionary, the
At the University of Texas Linguistic Research Center: List of online
books, Indo-European Lexicon
Proto-Indo-European Lexicon at the University of Helsinki, Department
of Modern Languages, Department of World Cultures, Indo-European
Syntax & Etymology Dictionary
Academia Prisca: 'Promoting North-West Indo-European as a modern
language since 2005, with continuous reference to the parent Late
Centum and satem
Glossary of sound laws
Sievers' (Edgerton's converse)
Parts of speech
Nominals (nouns and adjectives)
Indogermanisches etymologisches Wörterbuch (IEW)
Lexikon der indogermanischen Verben
Lexikon der indogermanischen Verben (LIV)
Lexikon der indogermanischen Partikeln und Pronominalstämme
Lexikon der indogermanischen Partikeln und Pronominalstämme (LIPP)
Nomina im Indogermanischen Lexikon
Nomina im Indogermanischen Lexikon (NIL)
Indo-European Etymological Dictionary (IEED)
Indo-European migrations & Proto-Indo-European Urheimat hypotheses
The king and the god
Encyclopedia of Indo-European Culture
Encyclopedia of Indo-European Culture (EIE)
History of English
Early Modern English
low unrounded vowels
low back vowels
high back vowels
high front vowels
changes before historic /l/
changes before historic /r/
BNF: cb11995173d (d