Indo-European copula copula (with corresponding voiceless and voiced fricatives) existed side by side in Germanic, and the involvement of a separate root "" is unnecessary. The root "*(s)teh-" meant "to stand". From this root comes the present stem of the so-called "substantive verb" in Irish and Scottish Gaelic, "tá" and "tha" respectively. On the absence of the initial s- in Celtic, see Indo-European s-mobile. In Latin, "stō, stare" retained the meaning "to stand", until local forms of Vulgar Latin began to use it as a copula in certain circumstances. Today, this survives in that several Romance languages (Galician-Portuguese, Spanish, Catalan) use it
Indo-European migrations of migration fit the distribution of Indo-European languages, and how closely the sociological model of the original society reconstructed from Proto-Indo-European lexical items fits the archaeological profile. Since the early 1980s the mainstream consensus among Indo-Europeanists favors Marija Gimbutas' "Kurgan hypothesis", c.q. David Anthony's "Revised Steppe theory", derived from Gimbutas' pioneering work, placing the Indo-European homeland in the Pontic steppe, more specifically, between the Dniepr (Ukraine) and the Ural river (Russia), of the Chalcolithic period (4th to 5th millennia BCE), where various related cultures developed. The Pontic steppe is a large area of grasslands in far Eastern Europe, located north