One of the dangers of learning Greek is that after a while you feel like you have a handle on things and don’t need to keep reviewing grammar. Then over time you lose some of the nuances of the language and start letting a broad, general understanding govern everything you read.
Take for example the imperfect. It always designates a continuous action, usually in the past. Right? We learn that in first year Greek, and then in second year we are introduced to the concepts of narrow-band and broad-band imperfects. In other words, the imperfect is always continuous albeit for shorter or longer periods of time.
In the narrow-band, Daniel Wallace lists uses such as progressive (the default) and ingressive (beginning to do something), and then broad-band such as iterative (repeated action), customary (habitual action not necessarily tied to one point in time), conative (desiring or attempting to do something), and then the weird use of the retained imperfect in indirect discourse.
The point is that all of these indicate a continuous action in one way or another.
But what about ελεγεν?