High Quality Content by WIKIPEDIA articles! The roots of the reconstructed Proto-Indo-European language (PIE) are basic parts of words that carry a lexical meaning, so-called morphemes. PIE roots always have verbal meaning like "to eat" or "to run", as opposed to nouns ("a foot"), adjectives ("red"), or other parts of speech. Roots never occur alone in the language. Complete inflected words like verbs, nouns or adjectives are formed by adding further morphemes to a root. Typically, a root plus a suffix forms a stem, and adding an ending forms a word.