What would happen if….

What would happen if a person from 500 years ago was brought to the present times?  Would they be able to communicate?  What was written 500 years back in “plain” english would now be close to unintelligible to modern day “American English, and also “British English”.  And they would not understand our language for the most part, in my opinion.  Anyone care to add in what you think to this idea?