In my opinion…all questions are fair. 

So let’s help each other out.

Question 1:  If we went back to ancient Rome would they understand English?

Answer: 

No.  

English did not exist. 

English in fact is fairly new.  In fact, I am quite sure that if we go back a few hundred years, the pronounciation of English words would be quite hard to understand to us today.  If we went back even further, it would be incomprehensible.  Though English is based on Latin roots, we have a whole lot built on German, French, and just recently Spanish words building on top of that latin foundation.  Hamish Gregor corrected me on this.  See his comments included with this post.  He is right, English has its roots based on Germanic languages.   We do have various Latin words mixed in, AND French, AND assorted others.   Thx Hamish for the insight.   

I might suggest that your question should be restated:

Restated Question 1:  If we went back to Ancient Rome COULD WE UNDERSTAND LATIN?

Now that is a question. 

I am pretty sure it would be possible, but not without intense study.  As I said in my podcast, drop  a Catholic priest or a classical scholar through our time portal just a block from the ancient Roman Forum, and I doubt that even they would understand the Latin being spoken — at least not right away.    There was a high Latin and a low Latin of the streets.   Just as there was the Cockney dialect and Oxford English. 

My hypothesis comes from an English COED that was attending my high school back in the 70s.  She was speaking English…no doubt about it…and she had to repeat the same sentence over and over to me so that I could understand her.  I finally had to tell her that I did not understand.  I did not want to hurt her feelings, but I really couldn’t comprehend what she was saying.

So a couple of hundred years, and an ocean caused a communciation problem, what would a couple of thousand years have done?

Any of our Latin scholars care to expand on this?