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
Ancient history of Afghanistan of the Indo-Aryans drifted much further west as with the Mitanni. The Iranians dominated the modern day plateau, while the Indo-Aryans ultimately headed towards the Indian subcontinent. The Avesta is believed to have been composed possibly as early as 1800 BC and written in ancient Ariana (Aryana), the earliest name of Afghanistan which indicates an early link with today's Iranian tribes to the west, or adjacent regions in Central Asia or northeastern Iran in the 6th century BC. Due to the similarity between early Avestan and Sanskrit (and other related early Indo-European languages such as Latin and Ancient Greek), it