One of the remarkable features of ancient Greek is its tendency to use the optative with ἂν in circumstances in which English would use a more direct statement or question with present or future indicative. When judged in relation to time (as has been usual for several centuries) this optative is in some circumstances seen to have past reference, but there was from Homer through to the classical period a growing tendency for such ‘past’ potentials to be expressed by means of the past tenses of the indicative. My studies in Greek aspect have led me to discount the time element in considering the ancient Greek verb, and I have stated in my Greek Grammar for Students that even in potential statements using the indicative the distinction between the imperfect, aorist and pluperfect tenses ‘is purely that of aspect, the time reference being understood from the context’. In this paper I wish to explore this area a little more and to make some suggestions about some uses of the imperfect tense which I now see are related to the development of potential expressions.