The Polish language is the official language of the Republic of Poland, and it is spoken as a first language of the vast majority of its citizens. The Polish language (along with Slovak and Czech) belongs to the West Slavic group of the Slavic subfamily of Indo-European languages. Linguists believe that the Slavic languages have retained the features of the original Proto-Indo-European language to a much greater degree than have the Germanic and Romance languages. The spoken Slavic languages also show more similarity among themselves than do the Germanic or the Romance languages.