Short answers, pulled from the story.
Early Modern English spans from the late 15th century, around the time of William Caxton's printing press in Westminster in 1476, to the mid-to-late 17th century, when Modern English is considered to have emerged fully by the Georgian era in 1714.
Early Modern English is colloquially called Shakespeare's English or King James' English because its most widely read surviving texts are Shakespeare's plays and the King James Bible of 1611. Both works have remained comprehensible to modern readers and directly shaped the development of Standard English.
The King James Version, published in 1611 and begun in 1604, was largely based on the Bishops' Bible translation and revision of 1602. Its translators kept the singular pronoun "thou" to match the Hebrew and Ancient Greek distinction between singular and plural second person, not to express reverence. The Geneva Bible's popularity had directly prompted its creation.
Early Modern English spelling was unstable: the word "he" could appear as both "he" and "hee" in the same sentence. The letters "u" and "v" were variants of one letter, with "u" typically at the start of words, and "i" and "j" were similarly interchangeable. The modern convention of separating consonant and vowel forms for both pairs appears to have been introduced in the 1630s.
Early Modern English was rhotic, meaning the "r" after vowels was pronounced; it was not lost until the late 1700s. Consonant clusters like "wr" in write, "kn" in knife, and "hw" in what were still fully pronounced. The vowel system was also different: Shakespeare rhymed "haste" and "last", and "doom" and "come" rhymed in some pronunciations due to early vowel shortening.
"Thou" was the informal singular second-person pronoun and was in common use in the early 16th century. By 1650 it sounded old-fashioned or literary. Its disappearance meant that the past subjunctive became indistinguishable from the indicative past for all verbs except "to be", and it ironically gained a devotional association in later hymns and prayers it was never designed to carry.