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, and Proto-Indo-European pronouns are treated elsewhere.

PIE had eight or nine cases, three numbers (singular, dual and plural) and probably originally two genders (animate and neuter), 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 (called athematic stems) and exhibited a complex pattern of accent shifts and/or vowel changes (ablaut) among the different cases. Two declensions ended in a vowel (*-o/e-) 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 'giver' and *déh₃om 'gift' are derived from *deh₃- 'to give', but the practice was much more common in PIE. For example, *pṓds 'foot' was derived from *ped- 'to tread', and *dómh₂s 'house' from *demh₂- 'to build'.

...
Wikipedia