[1] possum, posse, potuī: to be able
Images #1 - #3: possum, posse is derived from a combination of potis (‘able’; ‘capable’) + esse:
Images #4 - #6: The same applies to the perfect, pluperfect and future perfect i.e. it is a combination of potis plus the perfect stem of esse i.e. fu¦ī; note the third person plural of the future perfect: potuerint
