Someone in r/nostupidquestions said this would be a good question for you guys, so here I am!
So, because of how languages evolve over time, there must be a point where if I went back in time, the English I speak now would be unrecognizable to English speakers of the past, right? I am just curious how far that is. At what point would I no longer be able to reasonably communicate with people?
At what point would I not even recognize a single word?
Could other languages go further back?
There’s been loads of questions like this.
A while ago I asked a similar question, about why Shakespeare in original pronunciation writing in the 16th century was generally mostly understandable (see this interesting Open University video here for some samples of Shakespeare in original pronunciation) but Chaucer writing in the 14th century only a couple of centuries previously (e.g., this excerpt from the Miller's Tale) sounded like a different language. I got a fantastic answer from /u/bloodswan, which was very enlightening about the changes in the English language during that period between Chaucer and Shakespeare.
Here's the FAQ section for this question: "How far back could I go and still communicate?"