sentences:  ", for example, might not have existed in PIE at all, if the Indo-European words usually traced back to it are onomatopoeias.The meaning of a reconstructed root is conventionally that of a verb; the terms "root" and "verbal root" are almost synonymous in PIE grammar.This is because, apart from a limited number of so-called root nouns, PIE roots overwhelmingly participate in verbal inflection through well-established morphological and phonological mechanisms.