As part of our culture and education, native English speakers are exposed to English written centuries ago, including some grammatical forms that have fallen out of use. We encounter them in Shakespeare, in the King James version of the Bible, and in books (and movies!) about King Arthur and Robin Hood. The old second person familiar pronoun was "thou," the second person verb ending was "-est," the third person ending was "-eth"--or something like that. We don't study them or use them correctly.
Some examples of old-fashioned English include:
"And Ruth said, Intreat me not to leave thee, or to return from following after thee: for whither thou goest, I will go; and where thou lodgest, I will lodge: thy people shall be my people, and thy God my God."
"The sun also ariseth, and the sun goeth down, and hasteth to his place where he arose. The wind goeth toward the south, and turneth about unto the north; it whirleth about continually, and the wind returneth again according to his circuits."
Mostly, we hear this kind of language in movies set in old times and sometimes we use it facetiously. "Fair damsel, wouldst thou hie thee with me to yon Dunkin' Donuts to quaff a flagon of coffee?"
In the same category, the sound of "th" was once given a separate letter of its own, the thorn (þ); in the commonest word that begins with th, "the," the word was written quickly and the thorn became distorted to look like a "y," and eventually printers used an actual "y." The result is that "The" was typeset as "Ye"--hence places that are trying to look old-fashioned may call themselves "Ye Olde Ice-Cream Shoppe."