#color(white)("XXXXXX")#Example:
Simple Past
#color(white)("XXX")#Joe ate the entire cake by himself.
Past Participle
#color(white)("XXX")#(in perfect forms)
#color(white)("XXX")#Joe had eaten then entire cake before Alice arrived.
#color(white)("XXXXxX")#Joe's eating of the cake occurred before the time (in the past) when Alice arrived.
#color(white)("XXX")#Joe has eaten the entire cake!
#color(white)("XXXXX")#At this point in time, Joe has finished eating the cake.
#color(white)("XXX")#Joe will have eaten the entire cake before Alice arrives.
#color(white)("XXXXXX")#Before the future event of Alice's arrival, Joe will have finished eating the cake.
#color(white)("XXX")#(in passive form)
#color(white)("XXX")#The cake was eaten before Alice arrived.