Misplaced Pages

Revision as of 18:35, 6 June 2006

The Proto-Indo-European language (PIE) is the hypothetical common ancestor of the Indo-European languages, believed to have been spoken around 4000 BC in Central Asia (according to the Kurgan hypothesis) or millennia before that in Anatolia (according to the Anatolian hypothesis). The existence of such a language is generally accepted by linguists, though there has been debate about many specific details.

Part of a series on
Indo-European topics
Languages List of Indo-European languages Extant Albanoid Albanian Armenian Balto-Slavic Baltic Slavic Celtic Germanic Hellenic Greek Indo-Iranian Indo-Aryan Iranian Nuristani Italic Romance Extinct Anatolian Tocharian Paleo-Balkan Dacian Illyrian Liburnian Messapic Mysian Paeonian Phrygian Thracian Reconstructed Proto-Indo-European language Phonology: Sound laws, Accent, Ablaut Hypothetical Balkanic Daco-Thracian Graeco-Albanian Graeco-Armenian Graeco-Aryan Graeco-Phrygian Indo-Hittite Italo-Celtic Thraco-Illyrian Grammar Vocabulary Root Verbs Nouns Pronouns Numerals Particles Other Proto-Albanian Proto-Anatolian Proto-Armenian Proto-Germanic (Proto-Norse) Proto-Italo-Celtic (Proto-Celtic · Proto-Italic) Proto-Greek Proto-Balto-Slavic (Proto-Slavic · Proto-Baltic) Proto-Indo-Iranian (Proto-Iranian)
Philology Hittite inscriptions Hieroglyphic Luwian Linear B Rigveda Avesta Homer Behistun Greek epigraphy Phrygian epigraphy Messapic epigraphy Latin epigraphy Gaulish epigraphy Runic epigraphy Ogham Gothic Bible Bible translations into Armenian Tocharian script Old Irish glosses Albanian Kanun
Origins Homeland Proto-Indo-Europeans Society Religion Mainstream Kurgan hypothesis Indo-European migrations Eurasian nomads Alternative and fringe Anatolian hypothesis Armenian hypothesis Beech argument Indigenous Aryanism Baltic homeland Paleolithic continuity theory
Archaeology Chalcolithic (Copper Age) Pontic Steppe Domestication of the horse Kurgan Kurgan stelae Kurgan culture Steppe cultures Bug–Dniester Sredny Stog Dnieper–Donets Samara Khvalynsk Yamnaya Mikhaylovka culture Novotitarovskaya culture Caucasus Maykop East Asia Afanasievo Eastern Europe Usatovo Cernavodă Cucuteni Northern Europe Corded ware Baden Middle Dnieper Bronze Age Pontic Steppe Chariot Yamnaya Catacomb Multi-cordoned ware Poltavka Srubnaya Northern/Eastern Steppe Abashevo culture Andronovo Sintashta Europe Globular Amphora Corded ware Bell Beaker Únětice Trzciniec Nordic Bronze Age Terramare Tumulus Urnfield Lusatian South Asia BMAC Yaz Gandhara grave Iron Age Steppe Chernoles Europe Thraco-Cimmerian Hallstatt Jastorf Caucasus Colchian India Painted Grey Ware Northern Black Polished Ware
Peoples and societies Bronze Age Anatolian peoples (Hittites) Armenians Mycenaean Greeks Indo-Iranians Iron Age Indo-Aryans Indo-Aryans Iranians Iranians East Asia Wusun Yuezhi Europe Celts Gauls Celtiberians Insular Celts Cimmerians Hellenic peoples Italic peoples Germanic peoples Paleo-Balkan/Anatolia Thracians Dacians Illyrians Paeonians Phrygians Scythians Middle Ages East Asia Tocharians Europe Albanians Balts Slavs Norsemen/Medieval Scandinavians Middle Ages Indo-Aryan Medieval India Iranian Greater Iran
Religion and mythology Reconstructed Proto-Indo-European mythology Proto-Indo-Iranian paganism Historical Vedic religion Ancient Iranian religion Historical Hittite Indo-Aryan Vedic Hinduism Buddhism Jainism Sikhism Iranian Persian Zoroastrianism Kurdish Yazidism Yarsanism Scythian Ossetian Others Armenian European Paleo-Balkan (Albanian · Illyrian · Thracian · Dacian) Greek Roman Celtic Irish Scottish Breton Welsh Cornish Germanic Anglo-Saxon Continental Norse Baltic Latvian Lithuanian Slavic Practices Fire rituals Horse sacrifice Sati Winter solstice/Yule
Indo-European studies Scholars Marija Gimbutas J. P. Mallory Institutes Copenhagen Studies in Indo-European Publications Encyclopedia of Indo-European Culture The Horse, the Wheel, and Language Journal of Indo-European Studies Indogermanisches etymologisches Wörterbuch Indo-European Etymological Dictionary
v t e

All Indo-European languages are inflected languages (although many modern Indo-European languages, including Modern English, have lost much of their inflection). By comparative reconstruction, it is quite likely that at least the latest stage of the common PIE mother languages (Late PIE) was an inflectional language, which was more suffixing than prefixing.

However, by means of internal reconstruction and morphological (re-)analysis of the reconstructed, seemingly most ancient PIE word forms, it has recently been shown to be very probable that at a more distant stage PIE (Early PIE) may have been a root-inflected language, as was Proto-Semitic. As a consequence, it seems to be highly probable that PIE once was of the root-and-pattern morphological type (literature: Pooth (2004): "Ablaut und autosegmentale Morphologie: Theorie der uridg. Wurzelflexion", in: Arbeitstagung "Indogermanistik, Germanistik, Linguistik" in Jena, Sept. 2002).

Discovery and Reconstruction

PIE was first proposed in the 18th century AD as the basal language for the Indo-European languages then known, which included Latin, Greek, and Sanskrit. PIE did not account for the language families Anatolian and Tocharian; in addition to being unknown then, the two were never spoken either in India or in Europe, and they most likely branched away from their common ancestor millennia prior to the root of PIE as formerly defined. It also did not account for PIE's hypothesized laryngeal consonants—only after the discovery of these consonants in ancient the Hittite Language did they become an accepted part of the theory. But by common consent, Anatolian and Tocharian have always been accepted as "Indo-European". As a result, reconstructions of PIE's character, history, and homeland now take Anatolian and Tocharian into account. (Note that a sequence of Anatolian exit first and Tocharian exit second from PIE is compatible with both hypotheses on Indo-European origins.)

There is no direct evidence of PIE, because it was never written down. All PIE sounds and words are reconstructed from later Indo-European languages using the comparative method and the method of internal reconstruction. The asterisk is used to mark reconstructed PIE words, such as *wódr̥ "water", *ḱwṓn "dog", or *tréyes "three (masculine)". Many of the words in the modern Indo-European languages seem to have derived from such "protowords" via regular sound changes (e.g., Grimm's law).

Relationship to other language families

Many higher-level relationships between PIE and other language families have been proposed. Due to the great time depths, there is necessarily a great deal of speculation involved, and as a result the proposals are very controversial. Perhaps the most widely accepted proposal is of an Indo-Uralic family, encompassing PIE and Uralic. The evidence usually cited in favor of this is the proximity of the proposed Urheimaten of the two families, the typological similarity between the two languages, and a number of apparent shared morphemes. Frederik Kortlandt, while advocating a connection, concedes that "the gap between Uralic and Indo-European is huge", while Lyle Campbell, an authority of Uralic, denies any relationship exists. Other proposals, further back in time (and correspondingly less accepted), model PIE as a branch of Indo-Uralic with a Caucasian substratum; link PIE and Uralic with Altaic and certain other families in Asia, such as Korean, Japanese, Chukotko-Kamchatkan and Eskimo-Aleut (representative proposals are Nostratic and Joseph Greenberg's Eurasiatic); or link some or all of these to Afro-Asiatic, Dravidian, etc., and ultimately to a single Proto-World family (nowadays mostly associated with Merritt Ruhlen). Various proposals, with varying levels of skepticism, also exist that join some subset of the putative Eurasiatic language families and/or some of the Caucasian language families, such as Uralo-Siberian, Ural-Altaic (once widely accepted but now largely discredited), Proto-Pontic, etc.

Development

As the Proto-Indo-European language broke up, its sound system diverged as well, according to various sound laws in the daughter languages. Notable among these are Grimm's law and Verner's law in Proto-Germanic, loss of prevocalic *p- in Proto-Celtic, loss of prevocalic *s- in Proto-Greek, Brugmann's law in Proto-Indo-Iranian. Grassmann's law and Bartholomae's law may or may not have been still common Indo-European.

Phonology

Proto-Indo-European is conjectured to have used the following phonemes. See Indo-European languages for a summary of how these sounds evolved in the various Indo-European languages.

Consonants

The table gives the most common notation in modern publications. Variant transcriptions are given below. Raised ʰ stands for aspiration. According to the glottalic theory, the "voiced stops" of the system as described above were glottalic, perhaps ejectives, while the "voiced aspirated stops" may not have been voiced.

• Proto-Celtic, Proto-Balto-Slavic, Albanian, and Proto-Iranian merged the voiced aspirated series bʰ, dʰ, ǵʰ, gʰ, gʷʰ with the plain voiced series b, d, ǵ, g, gʷ. (However, Proto-Celtic did not merge gʷʰ and gʷ - the first became g while the second became b).
• Proto-Germanic underwent Grimm's law, changing voiceless stops into fricatives, devoicing unaspirated voiced stops, and de-aspirating voiced aspirates.
• Grassmann's law (Tʰ-Tʰ > T-Tʰ, e.g. dʰi-dʰeh₁- > di-dʰeh₁-) and Bartholomae's law (TʰT > TTʰ, e.g. budʰ-to- > bud-dʰo-) describe the behaviour of aspirates in particular contexts in some early daughter languages.

Labials

p, b, bʰ, grouped with the cover symbol P. b was a very rare phoneme, which is one argument in favor of the glottalic theory - it seems that languages having ejective stops tend not to have an ejective labial stop p'.

Coronals/Dentals

The standard reconstruction identified three coronal/dental stops: t, d, dʰ. They are symbolically grouped with the cover symbol T.

Some theorists conclude that consonant clusters of the form TK would undergo a metathesis in the proto-language, resulting in Kþ, compare Hittite dagan "earth" with Greek khthōn "earth", from ǵʰðōm, from earlier

• dʰǵʰoms, Hittite hartagas "monster", Greek arktos "bear" from hrkþos from earlier hrtgos. Both metathetized and unmetathetized forms survive in different ablaut grades of the root dʰégʷʰ "burn" (cognate to dagaz, day) in Sanskrit, dáhati "is being burnt" < dʰégʷʰ-e- and kṣā́yat "burns" < dʰgʷʰ-éh₁-.

Dorsals

Direct comparison, informed by the Centum-Satem isogloss yields the reconstruction of three rows of dorsal consonants in PIE.

• Palatovelars, ḱ, ǵ, ǵʰ (also transcribed k', g', g'ʰ or k̑, g̑, g̑ʰ or k̂, ĝ, ĝʰ). These were - or -like sounds which underwent a characteristic change in the Satem languages; they were possibly palatalized velars (, ) in Proto-Indo-European.
• Pure velars, k, g, gʰ.
• Labiovelars, kʷ, gʷ, gʷʰ (also transcribed k, g, g). Raised ʷ stands for labialization, or lip-rounding accompanying the articulation of velar sounds ( is a sound similar to English qu in queen).

The centum group of languages merged the palatovelars ḱ, ǵ, ǵʰ with the plain velars k, g, gʰ while the satem group of languages merged the labiovelars kʷ, gʷ, gʷʰ with the plain velars k, g, gʰ.

The existence of the plain velars as phonemes separate from the palatovelars and labiovelars has been disputed. In most circumstances they appear to be allophones resulting from the neutralization of the other two series in particular phonetic circumstances. It is difficult to pinpoint exactly what the circumstances of the allophony are, although it is generally accepted that neutralization occurred after s and u, and often before r. Most PIE linguists believe that all three series were distinct by late Proto-Indo-European, although a minority, including Frederik Kortlandt, believe that the plain velar series was a later development of certain satem languages; this view was originally articuled by Antoine Meillet in 1894. Those who support the view of the threefold distinction in PIE cite evidence from Albanian (Holger Pedersen, KZ 36 (1900) 277-340; Norbert Jokl, Mélanges linguistiques offerts à M. Holger Pedersen (1937) 127-161) and Armenian (Vittore Pisani, Ricerche Linguistiche 1 (1950) 165ff.) that they treated plain velars differently from the labiovelars in at least some circumstances, as well as the fact that Luwian apparently has distinct reflexes of all three series: *ḱ > z (probably ); *k > k; *kʷ > ku (probably ) (Craig Melchert, Studies in Memory of Warren Cowgill (1987) 182–204). Kortlandt, however, disputes the significance of this evidence (Recent developments in historical phonology (1978) 237-243 = ). Ultimately, this dispute may be irresoluble -- analogical developments tend to quickly obscure the original distribution of allophonic variants that have been phonemicized, and the time frame is too great and the evidence too meager to make definite conclusions as to when exactly this phonemicization happened.

Fricatives

s (with the voiced allophone z). The "laryngeals" may have been fricatives, but there is no consensus as to their phonetic realization. There were also fricative allophones of t, d, usually transcribed þ, ð.

Laryngeals

The symbols h₁, h₂, h₃, with cover symbol H (or ə₁, ə₂, ə₃ and ə), stand for three hypothetical "laryngeal" phonemes. There is no consensus as to what these phonemes were, but it is widely accepted that h₂ was probably uvular or pharyngeal, and that h₃ was labialized. Commonly cited possibilities are ʔ ʕ ʕʷ and x χ~ħ xʷ; there is some evidence that h₁ may have been two consonants, ʔ and h, that fell together.

The schwa indogermanicum symbol ə is commonly used for a laryngeal between consonants.

Nasals and Liquids

r, l, m, n, with vocalic allophones r̥, l̥, m̥, n̥, grouped with the cover symbol R.

Semivowels

w, y (also transcribed u̯, i̯) with vocalic allophones u, i.

Vowels

• Short vowels a, e, i, o, u
• Long vowels ā, ē, ō; a colon (:) is sometimes employed to indicate vowel length instead of the macron sign (a:, e:, o:).
• Diphthongs ai, au, āi, āu, ei, eu, ēi, ēu, oi, ou, ōi, ōu
• vocalic allophones of consonantal phonemes: u, i, r̥, l̥, m̥, n̥.

Other long vowels may have appeared already in the proto-language by compensatory lengthening: ī, ū, r̥̄, l̥̄, m̥̄, n̥̄.

It is often suggested that all a sounds (short and long) were earlier derived from an e preceded or followed by h₂, but Mayrhofer (1986: 170 ff.) has argued that PIE did in fact have a and ā phonemes independent of h₂.

Ablaut

Indo-European had a characteristic general ablaut sequence that contrasted the vowel phonemes o/e/Ø through the same root.

Noun

Nouns were declined for eight cases (nominative, accusative, genitive, dative, instrumental, ablative, locative, vocative). There were three genders: masculine, feminine, and neuter.

There are two major types of declension, thematic and athematic. Thematic nominal stems are formed with a suffix -o- (in vocative -e) and the stem does not undergo ablaut. The athematic stems are more archaic, and they are classified further by their ablaut behaviour (acro-dynamic, protero-dynamic, hystero-dynamic and holo-dynamic, after the positioning of the early PIE accent (dynamis) in the paradigm).

Case endings:

Pronoun

PIE pronouns are difficult to reconstruct due to their variety in later languages. This is especially the case for demonstrative pronouns.

PIE had personal pronouns in the first and second person, but not the third person, where demonstratives 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. According to Beekes (1995), there were also two varieties for the accusative, genitive and dative cases, a stressed and an enclitic form.

As for demonstratives, Beekes (1995) tentatively reconstructs a system with only two pronouns: so/seh₂/tod "this, that" and h₁e/ (h₁)ih₂/(h₁)id "the (just named)" (anaphoric). He also postulates three adverbial particles ḱi "here", h₂en "there" and h₂eu "away, again", from which demonstratives were constructed in various later languages.

There was also an interrogative/indefinite pronoun with the stem kʷe-/kʷi- (adjectival kʷo-), and probably a relative pronoun with the stem yo-. A third-person reflexive pronoun se (acc.), sewe, sei (gen.), sébʰio, soi (dat.), parallel to the first and second person singular personal pronouns, also existed, as well as possessive pronominal adjectives.

PIE had a separate set of endings for pronouns; many of these were later borrowed as nominal endings.

Verb

The Indo-European verb system is complex and exhibits a system of ablaut, as is still visible in the Germanic languages (among others)—for example, the vowel in the English verb to sing varies according to the conjugation of the verb: sing, sang, and sung.

The system is clearly represented in Ancient Greek and Vedic Sanskrit, two of the most completely attested of the early daughter languages of Proto-Indo-European.

Verbs have at least four moods (indicative, imperative, subjunctive and optative, as well as possibly the injunctive, reconstructible from Vedic Sanskrit), two voices (active and mediopassive), as well as three persons (first, second and third) and three numbers (singular, dual and plural). Verbs are conjugated in at least three "tenses" (present, aorist, and perfect), which actually have primarily aspectual value. Indicative forms of the imperfect and (less likely) the pluperfect may have existed. Verbs were also marked by a highly developed system of participles, one for each combination of tense and mood, and an assorted array of verbal nouns and adjectival formations.

A number of secondary forms could be created, such as the causative, intensive and desiderative; technically these were part of the derivational system rather than the inflectional system, as they existed only for certain verbs and did not necessarily have completely predictable meanings (compare the remnants of causative constructions in English – to fall vs. to fell, to sit vs. to set, to rise vs. to raise and to rear). The above-mentioned verbal nouns and adjectives were likewise part of the derivational system (compare the formation of verbal nouns in English, using -tion, -ence, -al, etc.), and it appears that the same originally applied to the different verb tenses. Some verbs in Ancient Greek still have perfect tenses with unpredictable meanings – from histēmi "I set, I cause to stand": hestēka "I am standing"; from mimnēiskō "I remind": memnēmai "I remember"; from peithō "I persuade": pepoitha "I trust" as well as pepeika "I have persuaded"; from phūō "I produce": pephūka "I am (by nature)". The present tense in Ancient Greek and in Sanskrit is formed by the unpredictable addition of one of a number of suffixes (at least 10, in Sanskrit; at least 6, in Greek) to the verbal root; the aorist and perfect are likewise formed, in each case from their own set of suffixes (7 for the Sanskrit aorist, at least 3 for the Greek aorist), with little or no relation between the suffixes used in one tense and in another. (The perfect tense in Latin is likewise unpredictable, formed in one of at least six ways.) Sometimes more than one suffix can be applied to the same root, producing different present, aorist and/or perfect stems for the same verb, sometimes with the same meaning, sometimes with different meanings (see the above example with the Greek verb peithō). All of this suggests that the various tenses were originally independent lexical formations, similarly to the way that verbal nouns in English are formed unpredictably in English from different suffixes, sometimes with two or more formations that may differ in meaning: reference vs. referral, transference vs. transferral vs. transfer, recitation vs. recital, delivery vs. deliverance etc. (This is more understandable if one considers that the original meaning of these tenses was aspectual.) Only later, and gradually, were these various forms combined into a single set of inflectional paradigms. Vedic Sanskrit had still not completed the process, and even Ancient Greek has places where the old unorganized system still shows through. (As a result, verbs in Vedic Sanskrit have the appearance at first glance of a fantastically complex and disorganized system, with numerous redundancies combined with inexplicable holes. The system of PIE must have looked even more strongly like this.)

The primary distinction in verbs between the different ways of forming the present tenses was between thematic (ō) classes, with a "thematic" vowel o or e before the endings, and athematic (mi) classes, with endings added directly to the root. The endings themselves differed somewhat, at the very least in the first-person singular, with the endings as indicated (ō vs. mi). Traditional accounts say that this is the only form where the endings differed, except for the presence or absence of the thematic vowel; but some newer researchers, e.g. Beekes (1995), have proposed a totally different set of thematic endings, based primarily on Greek and Lithuanian. These proposals are still controversial, however.

The original meanings of the past tenses (aorist, perfect and imperfect) are often assumed to match their meanings in Greek. That is, the aorist represents a single action in the past, viewed as a discrete event; the imperfect represents a repeated past action or a past action viewed as extending over time, with the focus on some point in the middle of the action; and the perfect represents a present state resulting from a past action. This corresponds, approximately, to the English distinction between "I ate", "I was eating" and "I have eaten", respectively. (Note that the English "I have eaten" often has the meaning, or at least the strong implication, of "I am in the state resulting from having eaten", in other words "I am now full". Similarly, "I have sent the letter" means approximately "The letter is now (in the state of having been) sent". However, the Greek, and presumably PIE, perfect, more strongly emphasizes the state resulting from an action, rather than the action itself, and can shade into a present tense.)

Note that in Greek the difference between the present, aorist and perfect tenses when used outside of the indicative (that is, in the subjunctive, optative, imperative, infinitive and participles) is almost entirely one of grammatical aspect, not of tense. That is, the aorist refers to a simple action, the present to an ongoing action, and the perfect to a state resulting from a previous action. An aorist infinitive or imperative, for example, does not refer to a past action, and in fact for many verbs (e.g. "kill") would likely be more common than a present infinitive or imperative. (In some participial constructions, however, an aorist participle can have either a tensal or aspectual meaning.) It is assumed that this distinction of aspect was the original significance of the PIE "tenses", rather than any actual tense distinction, and that tense distinctions were originally indicated by means of adverbs, as in Chinese. However, it appears that by late PIE, the different tenses had already acquired a tensal meaning in particular contexts, as in Greek, and in later Indo-European languages this became dominant.

The meanings of the three tenses in the oldest Vedic Sanskrit, however, differs somewhat from their meanings in Greek, and thus it is not clear whether the PIE meanings corresponded exactly to the Greek meanings. In particular, the Vedic imperfect had a meaning that was close to the Greek aorist, and the Vedic aorist had a meaning that was close to the Greek perfect. Meanwhile, the Vedic perfect was often indistinguishable from a present tense (Whitney 1924). In the moods other than the indicative, the present, aorist and perfect were almost indistinguishable from each other. (The lack of semantic distinction between different grammatical forms in a literary language often indicates that some of these forms no longer existed in the spoken language of the time. In fact, in Classical Sanskrit, the subjunctive dropped out, as did all tenses of the optative and imperative other than the present; meanwhile, in the indicative the imperfect, aorist and perfect became largely interchangeable, and in later Classical Sanskrit, all three could be freely replaced by a participial construction. All of these developments appear to reflect changes in spoken Middle Indo-Aryan; among the past tenses, for example, only the aorist survived into early Middle Indo-Aryan, which was later displaced by a participial past tense.)

Numbers

The numbers are generally reconstructed as follows:

Lehmann (1993, 252-255) believes that the numbers greater than ten were constructed separately in the dialects groups and that *ḱm̥tóm originally meant "a large number" rather than specifically "one hundred."

Sample texts

As PIE was spoken by a prehistoric society, no genuine sample texts are available, but since the 19th century modern scholars have made various attempts to compose example texts for purposes of illustration. These texts are educated guesses at best; Calvert Watkins in 1969 rightly observes that in spite of its 150 years' history, comparative linguistics is not in the position to reconstruct a single well-formed sentence in PIE. Nevertheless, such texts do have the merit of giving an impression of what a coherent utterance in PIE might have sounded like.

Published PIE sample texts:

• Schleicher's fable (Avis akvasas ka) by August Schleicher (1868), modernized by Hermann Hirt (1939) and Winfred Lehmann and Ladislav Zgusta (1979)
• The king and the god (rēḱs deiwos-kʷe) by S. K. Sen, E. P. Hamp et al. (1994)

See also

• Proto-Indo-Europeans
• Proto-Semitic
• List of Indo-European roots
• Ur language

References

• Beekes, Robert S. P. (1995). Comparative Indo-European Linguistics: An Introduction. Amsterdam: John Benjamins. ISBN 90-272-2150-2 (Europe), ISBN 1-55619-504-4 (U.S.).
• Buck, Carl Darling (1933). Comparative Grammar of Greek and Latin. Chicago: University of Chicago Press. ISBN 0-22607-931-7.
• Lehmann, W., and L. Zgusta. 1979. Schleicher's tale after a century. In Festschrift for Oswald Szemerényi on the Occasion of his 65th Birthday, ed. B. Brogyanyi, 455–66. Amsterdam.
• Mayrhofer, Manfred (1986). Indogermanische Grammatik, i/2: Lautlehre. Heidelberg: Winter.
• Sihler, Andrew L. (1995). New Comparative Grammar of Greek and Latin. Oxford: Oxford University Press. ISBN 0-19-508345-8.
• Szemerényi, Oswald (1996). Introduction to Indo-European Linguistics. Oxford.
• Whitney, William Dwight (1924). Comparative Grammar of Greek and Latin. Delhi: Motilal Banarsidass Publishers Private Limited (reprint). ISBN 81-208-0621-2 (India), ISBN 0-48643-136-3 (Dover, US).

External links

• American Heritage Dictionary:
  • Indo-European and the Indo-Europeans, essay on the reconstruction of Proto-Indo-European
  • Indo-European Roots, index
• Indo-European Etymological Dictionary (Leiden University)
• Indo-European Documentation Center at the University of Texas
• "The Indo-Uralic Verb" by Frederik Kortlandt
• Say something in Proto-Indo-European (by Geoffrey Sampson)
• An Overview of the Proto-Indo-European Verb System (by Piotr Gąsiorowski)
• Christian prayers projected to PIE by Raphael Sawitzky.
• Other PIE example texts
• PIE root etymology database, compiled from Walde-Pokorny by L. Nikolayev and from Friedrich, Tischler (Hittite) and Adams (Tocharian) by Sergei Starostin.

• Bronze Age
• Indo-European
• Proto-languages