The Rook and Pawn Ending

Hi! This the tenth game of Irving Chernev book "The Most Instructive Games of Chess Ever Played".  The blog is part of my studies in the ChessDojo training program. The idea is to learn with this game to improve my chess. Important to say is: I make my analysis before read the Chernev chapter, obviously.  I need to clarify that I'm nobody in chess, rating 1164 FIDE, and what I wrote probably has some mistakes, I'm Brazilian and my English is weak, like squares. But feel free to comment this post and give me some aids. Best Regards!