I don't know what Greek scholar told you that, but they're full of baloney. The Greek manuscripts have no capitalization (and no punctuation, either) so any argument based on capitalization goes nowhere.
Here, let me help you out. The usual claim is that the Gk for "Peter" (Petros) and the immediately following word for "rock" (petra) mean something different, because there are a few examples of "petros" in classical Gk poetry (but none in the NT) which mean "pebble".
The argument is bogus because Jesus is forming a masculine proper name from "petra", a noun with feminine declension. He had to call Simon "Petros", or give him a woman's name. All the Petros/petra change proves is that Peter was a man.
"Cicero" comes from the Latin for "chickpea". "Now I know that you are 'Chickpea', and upon this rock I build ..." Huh?
"Friday, March 01, 2013 7:01:04 PM · 5 of 16 Cicero to knarf “Thou art Peter, and upon this Rock I will build my Church.”
capped it
All I did with "Cicero" is paraphrase his name as he was explaining Peter's name was being used in the scripture quote ... which as anyone can see ... equals ...
HUH ?
Peter, Cephas (Greek) or Kepha (Hebrew). Both Cephas and Kepha mean rock. “Kepha” would be close to what the Lord had named Peter.