Hi, check out this thread, which has several examples across different time periods, and links to a handful of other posts

• I am a native English speaker with a hypothetical time machine. How far back in time in England can I go and still communicate intelligibly with the locals?

and this one, where /u/bloodswan takes a deep dive into the Great Vowel Shift

• When I hear Chaucer spoken in Middle English, it almost sounds more like Dutch than English. But though Shakespeare is closer in time to Chaucer than the present, his English is much easier to understand. What happened to English in between, and why?

You might also be interested in checking out samples of writing from various periods, for example in The Norton Anthology of English Literature