No direct evidence of PIE exists; scholars have reconstructed PIE from its present-day descendants using the comparative method. For example, compare the pairs of words in Italian and English: piede and foot, padre and father, … 展开

The table lists the main Indo-European language families, comprising the languages descended from Proto-Indo-European.
Commonly proposed subgroups of Indo-European languages include Italo-Celtic, Graeco-Aryan 展开

Root
Proto-Indo-European roots were affix-lacking morphemes that carried the core lexical meaning of a word and were used to derive related words (cf. … 展开

• Indo-European vocabulary
• Proto-Indo-European verbs
• Proto-Indo-European pronouns
• List of Indo-European languages 展开

Scholars have proposed multiple hypotheses about when, where, and by whom PIE was spoken. The Kurgan hypothesis, first put forward in 1956 by Marija Gimbutas, has become the most popular. It proposes that the original speakers of PIE were the 展开

Proto-Indo-European phonology has been reconstructed in some detail. Notable features of the most widely accepted (but not uncontroversial) … 展开

The syntax of the older Indo-European languages has been studied in earnest since at least the late nineteenth century, by such scholars as 展开