I read Koine Greek well. I've had 4 semesters of Koine Greek, with one of the top Greek scholars in the world for my professor. He was also on many translation committees. He says that the KJV is the most corrupt version there is. He speaks modern Greek and used to show us the differences between modern Greek, Koine Greek & Ancient Greek. They are very different languages - different letters, grammar & vocabulary. I can understand a few things in modern Greek, but not enough to get the gist.
You could have googled that instead of just passing on information that is totally untrue!
Well, aren't you just special...
But I will say that the kjv is certainly not corrupt...your professor probably has a bias against it because of its take on holiness...he probably wants to have his cake and eat it, too....believing in a gospel that will save him from hell without saving him from sin first...for that he probably does not want to be saved from sin....he probably loves his sinful lifestyle and therefore does not want to give it up...which would account for a bias against the kjv...since the teaching of the kjv is that you cannot have your cake and eat it, too!
I will say that I read English quite well...
And that I believe that God, in His sovereignty, Omnipotence, and love is both able and willing to preserve His unadulterated message in Bibles that we can read in our own language.
So, I'm afraid that you put all of that effort into learning Greek for nothing...because you will get no less of the unadulterated message of the word of God by reading it in the English than if you read it in the Greek.
In fact, the "educated" scribes and Pharisees rejected Jesus while the common people heard Him gladly.
And thus the "educated" Greek and Hebrews scholars might be more inclined to reject Jesus and what He says to us than those who read His unadulterated word in the English language (the common people).