The English language. A History Fernando Trujillo. Main divisions. Old English From the first Anglo-Saxon settlements (500) to about 1100. Middle English From about 1100 to about 1500. Modern English From about 1500 to the present day. Origin of the language. The Germanic tribes.
In Old English, thou and thee were always singular, and ye and you always plural, but in Middle English times the custom arose of using ye/you as a polite or deferential way of addressing a single person, and this usage spread; thou and thee gradually dropped out of use in everyday speech, and finally disappeared (except in some regional dialects) round about 1700. The difference between ye and you was the same as that between he and him: one was nominative and the other accusative. This distinction was maintained until the sixteenth century (Barber, 2000: 123).
Fennell (2001: 1): “Typically, studies of the development of English (...) divide the language into four stages: Old English, Middle English, Early Modern English and Modern or Present Day English...The dates for the periods of English I have chosen (...) are as follows: Old English: CE 500-1100; Middle English: 1100-1500; Early Modern English: 1500-1800; Modern English: 1800-present”.