Asking questions that were previously asked is fine. Mentioning previous discussions is not intended to discourage more: further questions, info, and debate are welcome.

You can see "Could a modern english speak with a person from the medieval in england?" at https://www.reddit.com/r/AskHistorians/comments/7xa5rq/could_a_modern_english_speak_with_a_person_from/ . /u/cdesmoulins provided a lot of links to other discussions but then a discussion of their own. /u/Searocksandtrees provided other links there.

Citation of Due Credit: that link is from Searocksandtrees' reply to the current https://www.reddit.com/r/AskHistorians/comments/8aw6ea/if_i_was_to_go_back_in_time_to_medieval_england_c/ . That's mostly about Old English so far, which is before your time of interest.