With the RCC in shipwreck all over the world, why waste his time on trying to convince non-Catholics that Jesus was giving Peter extra-Scriptural authority over His Church? We understand that Jesus was referring to Peter's confession, "You are the Christ, the Son of the living God." That confesson concerning Jesus is the rock upon which He bulds the Church, certainly a stronger foundation than building it on a mere man, who had previously exhibited his weakness and sinfulness in denying Jesus.
And how do you know this? As Claud has admirably shown:
1) The distinction between Petros and petras did not exist in Koine Greek, which is the language of the New Testament, as opposed to Attic Greek which was already at that time an ancient language;The grammar, despite your desire to the contrary, clearly shows that our Lord was indeed referring to Peter as the rock upon which he would build his Church.2) the presence of taute as a modifyer of petras shows that it refers back to Petros;
3) that in any case John 1:42 shows that Petros is a translation of Kepha, this being the actual name that our Lord used in the passage and which can only mean 'Rock'.