Aspect: Perfective vs. Imperfective
The Greek verbal system is primarily aspect focused, not time focused like in English. The ideas of past, present, and future are the big ideas in the English verbal system. But in Greek, while time does exist, it is aspect that is the big overriding idea. So what is aspect?
Aspect refers to the way in which an action or event is viewed or perceived. One way to view an event is to look at it as a whole, maybe an overview as a whole complete unit. Another way to view the same event could be to be down inside the event and view it from within as it is unfolding. These are two possible ways to view the same event. These two different ways to view an event are a difference of aspect.
When an action or event is viewed as a whole or complete unit, this is called perfective aspect. When an action or event is viewed from within as it is unfolding, this is called imperfective aspect. So the same action or event can actually be described in both ways! Think of standing on a high mountain and looking out over a valley. You take the whole view in at one time. You see the valley as a whole. This is a very different thing to actually walking through the valley and experiencing it as you move through it. It’s the same valley, but a different view.
In Greek, aspect is called ὄψις (view). The perfective aspect is called ἀόριστος ὄψις (aorist aspect). The aorist aspect views the event as a whole, complete unit. The imperfective aspect is called παρατατικὴ ὄψις. Grammar books tend to mess this up when they give it an English name. They call this “present.” But this has nothing to do with time. So I often simply refer to these two aspects by their Greek names. After all, that’s what the Greeks did too.
Indicatives: Aorist vs Imperfect
Even though Greek is primarily an aspect focused language, there is still time involved when it comes to indicatives. Present indicatives describe (indicate) what is happening in the present time, while aorist and imperfect indicatives describe (indicate) what took place in the past. But even though indicatives are marked for time, the concept of aspect is still a big part.
Aorist and imperfect indicatives both describe events in the past. The difference between aorist and imperfect is a difference in aspect. The aorist indicative describes a past event as a whole, complete unit. This is the default past tense in Greek. In contrast, the imperfect indicative describes an event from within as it is unfolding.
If I say, “ἔφαγον τὸ μῆλον”, I have used the default simple past in Greek to describe the event. I ate the apple. The event cannot be described any simpler. The action is viewed as a completed whole. But if I say, “ἤσθιον τὸ μῆλον”, I am envisioning this event as unfolding. This might actually be the same event, but it is being described in two different ways. The reason why an author may choose one form over another is a topic for another time. But one simple reason could be based on the event or series of events themselves. ἔφαγον τὸ μῆλον is a good way to say what I did just now to the apple. But ἤσθιον μῆλον καθ ̓ ἡμέραν is a good way to say it if I ate an apple every day for a period of time.
In Greek, time is called χρόνος. The aorist indicative is called ἀόριστος χρόνος (aorist time) and the imperfect indicative is called παρατατικὸς χρόνος (imperfective time).
This is an explanation for why aorist and imperfect indicative would be chosen based on semantics or Aktionsart. There are also discourse reasons for using one form or another.
The aorist indicative is the default past time verb to use in narrative storytelling. However, the imperfect form is often used to introduce stories. Look at the starting sentences for two of the stories you are familiar with. The main verb in those initial sentences is imperfect, while all the following mainline events use the aorist.
(underlined = imperfect; highlight = aorist)
- The Lost Boy
παιδάριόν τι ἐζήτει ἀγορὰν ἐν πόλει μεγάλῃ. μὴ εὑρὸν αὐτὴν ἠρώτησεν ἄνδρα τινά· Ποῦ ἐστιν ἡ ἀγορά; ὁ δὲ ἀνὴρ ἔδειξεν αὐτῷ τὴν ὁδόν. εὑρὸν δὲ τὴν ἀγορὰν ἐχάρη τὸ παιδάριον.
- The Man And The Dragon
ἀνήρ τις περιεπάτει ἐν τῇ ὁδῷ, καὶ ἰδού, δράκων κείμενος ὑποκάτω δένδρου. ἥψατο ὁ ἀνὴρ τοῦ δράκοντος. ὁ δὲ δράκων ἠγέρθη καὶ ἐδίωξεν τὸν ἄνδρα. ἤγγισεν τῷ ἀνδρὶ καὶ ἔβαλεν πῦρ ἐκ τοῦ στόματος αὐτοῦ. ὁ δὲ ἀνὴρ ἔφυγεν τάχιον τοῦ δράκοντος καὶ ἐκρύβη ἐν ὕλῃ.