If you want to make Medieval, Renaissance or even characters from the age of Mozart believable, you have to be like a tightrope walker. Characters who say “thee” and “thou” can’t say also say “you” in the next sentence. Here is part of a poem by Geoffrey Chaucer, born in 1340, who wrote in Middle English. Book Of The Duchesse I have gret wonder, be this lighte, How that I live, for day ne nighte I may nat slepe wel nigh noght, I have so many an ydel thoght Purely for defaute of slepe That, by my trouthe, I take no kepe Of no-thing, how hit cometh or goth, Ne me nis no-thing leef nor loth. Al is y-liche good to me — Ioye or sorowe, wherso hyt be — For I have feling in no-thinge, But, as it were, a mased thing, Alway in point to falle a-...