Proto Indo-European language

Proto-Indo-European (PIE) is the linguistic reconstruction of the 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 of the knowledge concerning PIE since there is no written record of the language.

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. As Proto-Indo-Europeans became isolated from each other through the Indo-European migrations, the dialects of PIE spoken by the various groups diverged by undergoing certain sound laws and shifts in morphology to transform into the known ancient and modern Indo-European languages.

PIE had an elaborate system of morphology that included inflectional suffixes 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 also well-reconstructed. Today, the most widely-spoken daughter languages of PIE are Spanish, English, Hindustani (Hindi and Urdu), Portuguese, Bengali, Russian, Punjabi, German, Persian, French, Italian and Marathi.

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