A monolingual English speaker may find Modern Greek’s rigorous aspectual distinctions of simple/continuous/completed difficult, but students with knowledge of Ancient Greek are already familiar with these distinctions. They will also note that Modern Greek has extended the continuous/momentary distinction into the future tense, which is not true of Ancient Greek.

The history of this extension is the subject of Sandra Lucas’s dissertation and article:

Polarizing the future-the development of an aspectual opposition in the Greek future tense