thou – ты

thou (pron.) (староанглийское «þu»); из протогерманского «þu»; из PIE *tu-
2nd nominative singular personal pronoun, Old English þu, from Proto-Germanic *thu (source also of Old Frisian thu, Middle Dutch and Middle Low German du, Old High German and German du, Old Norse þu, Gothic þu), from PIE *tu-, second person singular pronoun (source also of Latin tu, Irish tu, Welsh ti, Greek su, Lithuanian tu, Old Church Slavonic ty, Sanskrit twa-m).

1675:
THOU (ðu, Sax., du, Du, Teut., tu, C.Br., tu, Lat.) – ты
В основе – тык, тыкаю.