How does a pendulum demonstrate energy conversions?

When the pendulum is pulled aside and held up, it has gravitational potential energy (due to its elevated position) but no kinetic energy (because it has no velocity). When it is dropped, the GPE is converted to KE; the pendulum takes on a lower position but greater velocity. The pendulum has maximum KE (and thus maximum velocity) when it has minimum GPE (and thus minimum elevation). But at all times the sum GPE + KE remains constant due to conservation of energy (except that friction with the air eventually brings the pendulum to rest).