Proto-Indo-European root原始印欧词根
Proto-Indo-European numeral原始印欧数词
Proto-Indo-European numerals原始印欧数词
Proto-Indo-European Obstruents原始印欧语阻塞音
Proto-Indo-European phonology原始印欧音系
Proto-Indo-European noun原始印欧名词
Proto-Indo-European accent原始印欧重音
Proto-Indo-European language原始印欧语
Proto-Indo-European roots原始印欧词根
N（名词） the prehistoric unrecorded language that was the ancestor of all Indo-European languages 原始印欧语