Between which points does the pendulum’s potential energy increase most?

it has the most potential energy when it reaches it's highest point, then stops... potential energy is when something builds up energy that is to be released... much like a roller coaster... when it's being drug up the track at the start, it's building up potential energy, and once it takes it's first drop is when all that potential energy turns into kinetic. same applies to a rubber band.

if you answer my question i will answer yours