" Singeth” wasn’t just a highfalutin flourish deployed to lend a sense of elevation and elegance to Shakespeare’s writings; “singeth” was a normal, boring way to say “sing” in the late sixteenth century. And it happened to be a holdover from Anglo-Saxon. We used “singeth” as the third-person form longer than we used “sings. "

― Kory Stamper , Word by Word: The Secret Life of Dictionaries