Language is evolving all the time. Describing something as naughty, awful, or terrific a couple centuries ago had very different connotations from what we now see today. And just as words (or non-words) are constantly popping up that would have meant nothing in the not-so-distant past, older parts of our language are also disappearing for good.
This video from the history-focused YouTube channel YesterVid explores how far back in time modern English-speakers would have to travel for their own language to become something they wouldn't recognize. Aside from not being able to understand some outdated slang terms, it wouldn't be too difficult to get by in the 18th and 19th centuries with the language skills we have now. The Great Vowel Shift took place during the 15th, 16th, and 17th centuries, so while you still would have been able to recognize a lot words of the time, understanding their pronunciation would have been half the battle. (You have this confusing period to thank for the different pronunciations of "ea" in words like "knead," "bread," and "great.")
Though conversing with fellow English speakers would have been a struggle prior to 1400, it's not until the turn of the first millennium that English might as well have been another language altogether. You can watch the full video above and subscribe to YesterVid for more history-filled content.
Header/banner images courtesy of YesterVid via YouTube.