He brought him to Jesus. Jesus looked at him, and said, "So you are Simon the son of John? You shall be called Cephas" (which means Peter). John 1:42
Kephas = Cephas = petra/petros = Peter
Petra and petros are the Greek forms of the Aramaic Kephas (Cephas), meaning rock, and are genderized. Peter is the anglicized form of petros. Genderization in this manner is not a part of the Aramaic languages. Therefore, the gender distinction found in the Greek is not valid but is a necessity of translation and usage.
See how that fits into your sentence diagramming.
Cephas is not the word used in Matthew where the RCC claims Peter to be called the ROCK
thats where it fits.