Compensatory lengthening

Compensatory lengthening affects first aorist forms whose verbal root ends in a sonorant (nasal or liquid: ν, μ, ρ, λ).^[3]

In Attic and Ionic Greek (also in Doric, with some differences), the σ in the first aorist suffix causes compensatory lengthening of the vowel before the sonorant, producing a long vowel (α → η or ᾱ, ε → ει, ι → ῑ, ο → ου, υ → ῡ).

In Aeolic Greek (which contributes some forms to Homeric), the σ causes compensatory lengthening of the sonorant instead of the vowel, producing a double consonant (ν → νν, λ → λλ).

The present stem sometimes undergoes sound changes caused by a suffix — for instance, -ι̯- (IPA: /j/, English consonantal y). In this case, the aorist is formed from the verbal root without the present-stem sound changes.

Kiparsky analyzes the process as debuccalization of s (σ) to h in Proto-Greek, metathesis of h and the sonorant so that h comes before the sonorant, and assimilation of h to the vowel (Attic-Ionic-Doric) or to the consonant (Aeolic).^[8]

• men-sa → men-ha (debuccalization) → mehna (metathesis) → mēna or menna (compensatory lengthening)

First aorist endings

Most of the active and middle forms of the first aorist contain an α. The indicative forms are similar to the imperfect, and the other moods, except for the subjunctive, are similar to the present, except with an α in the endings instead of an ο or ε. The first person singular indicative active, second person singular imperfect middle, the second person singular imperatives, infinitive active, and masculine nominative singular of the participle (bolded), however, do not follow this pattern. The subjunctive active and middle have endings identical to the present active and mediopassive, while the passive has endings identical to the present active.

Most of the passive forms of the first aorist have endings similar to those of the root aorist.

Zero-grade

When the present has a diphthong (e.g., ει), the second aorist has the offglide of the diphthong (ι).

• present λείπω "leave", aorist λιπ(ο⁄ε)- (e-grade in present, zero-grade in aorist)

When there is no vowel in the present stem besides the e of ablaut, the aorist has no vowel, or has an α from a vocalic ρ or λ.

• present πέτομαι "fly", aorist πτ(ο⁄ε)- (e-grade in present, zero-grade in aorist)
• present τρέπω, aorist τραπ(ο⁄ε)- (e-grade ρε in present, zero-grade ρ → ρα in aorist)

Reduplication

Present stems of verbs with a reduplicated aorist often do not have e-grade or an infix or suffix.

• present ἄγω "lead", aorist ἄγαγ(ο⁄ε)- (bare stem in present, reduplicated stem in aorist)

Second aorist endings

The endings include an ο or ε (thematic vowel). In the indicative, endings are identical to those of the imperfect; in non-indicative moods, they are identical to those of the present.

Second aorist passive

A second aorist passive is distinguished from a first aorist passive only by the absence of θ. A few verbs have passive aorists in both forms, usually with no distinction in meaning;^[11] but ἐφάνην "I appeared" is distinguished from ἐφάνθην "I was shown".

There is no correlation between the first/second aorist distinction in the active and the passive: a verb with an active second aorist may have a passive first aorist or vice versa.

Ingressive

In verbs denoting a state or continuing action, the aorist may express the beginning of the action or the entrance into the state. This is called ingressive aorist (also inceptive or inchoative).^[19]

• βασιλεύω "I am king" (present) — ἐβασίλευσα "I became king" or "I ruled" (aorist)

  basileúō — ebasíleusa

Resultative

The resultative aorist expresses the result of an action.^[20] Whether this is truly distinguishable from the normal force of the narrative aorist is disputable.

• ἐβούλευον "I was deliberating" is imperfect; ἐβούλευσα "I decided" is aorist.

Narrative

The aorist and the imperfect are the standard tenses for telling a story. The ordinary distinction between them is between an action considered as a single undivided event and the action as a continuous event. Thus, for example, a process as a whole can be described in the imperfect, while the individual steps in that process will be aorist.

• ἔπαιζε ἐν τῇ κώμῃ ταύτῃ ... μετ᾽ ἄλλων ἡλίκων ἐν ὁδῷ. καὶ οἱ παῖδες παίζοντες εἵλοντο ἑωυτῶν βασιλέα εἶναι τοῦτον δὴ ... ὁ δὲ αὐτῶν διέταξε τοὺς μὲν οἰκίας οἰκοδομέειν, τοὺς δὲ δορυφόρους εἶναι, τὸν δέ κου τινὰ αὐτῶν ὀφθαλμὸν βασιλέος εἶναι, τῷ δὲ τινὶ τὰς ἀγγελίας φέρειν ἐδίδου γέρας,...
  [Cyrus] was playing in this village... in the road with others of his age. The boys while playing chose to be their king this one.... Then he assigned some of them to the building of houses, some to be his bodyguard, one doubtless to be the King's Eye; to another he gave the right of bringing him messages;....

  Herodotus, Histories 1.114

Here the imperfect ἔπαιζε "was playing" is the whole process of the game (which continues past these extracts); the aorists the individual steps.^[21]

The narrative aorist has the same force, of an undivided or single action, when used by itself:

• ἐπεὶ δὲ εἶδον αὐτὸν οἵπερ πρόσθεν προσεκύνουν, καὶ τότε προσεκύνησαν, καίπερ εἰδότες ὅτι ἐπὶ θάνατον ἄγοιτο.
  And when the men who in former days were wont to do him homage saw him, they made their obeisance even then, although they knew that he was being led forth to death.

  6.10

Were wont to do him homage is the imperfect, made their obeisance the aorist, of προσκυνῶ "kowtow".

Complexive

On the other hand, if the entire action is expressed, not as a continuous action, but as a single undivided event, the aorist is used:^[21]

Herodotus introduces his story of Cyrus playing with:

• καὶ ὅτε ἦν δεκαέτης ὁ παῖς, πρῆγμα ἐς αὑτὸν τοιόνδε γενόμενον ἐξέφηνέ μιν·
  Now when the boy was ten years old, the truth about him was revealed in some such way as this:

  Herodotus, Histories 1.114

The aorist is also used when something is described as happening for some definite interval of time; this particular function can be more precisely called the temporal aorist:

• Οὑμὸς πατὴρ Κέφαλος ἐπείσθη μὲν ὑπὸ Περικλέους εἰς ταύτην γῆν ἀφικέσθαι, ἔτη δὲ τριάκοντα ᾤκησε.
  My father Cephalus was persuaded by Pericles to come to this land and lived (there) thirty years.

  Lysias, Against Eratosthenes 4

Past-in-the-past

The other chief narrative use of the aorist is to express events before the time of the story:^[22]

• τούς τε Ἱμεραίους ἔπεισαν ξυμπολεμεῖν καὶ αὐτούς τε ἕπεσθαι καὶ τοῖς ἐκ τῶν νεῶν τῶν σφετέρων ναύταις ὅσοι μὴ εἶχον ὅπλα παρασχεῖν (τὰς γὰρ ναῦς ἀνείλκυσαν ἐν Ἱμέρᾳ)
  they persuaded the Himeraeans to join in the war, and not only to go with them themselves but to provide arms for the seamen from their vessels (for they had beached their ships at Himera)

  Thucydides, History of the Peloponnesian War 7.1.3

It thus often translates an English or Latin pluperfect: the Greek pluperfect has the narrower function of expressing a state of affairs existing at the time of the story as the result of events before the time of the story.

Gnomic

The gnomic aorist expresses the way things generally happen, as in proverbs.^[23] The empiric aorist states a fact of experience (ἐμπειρίᾱ empeiríā), and is modified by the adverbs often, always, sometimes, already, not yet, never, etc.^[24] (English tends to express similar timeless assertions with the simple present.)

The gnomic aorist is regarded as a primary tense in determining the mood of verbs in subordinate clauses.^[25] That is to say, subordinate clauses take the subjunctive instead of the optative.

• οἱ τύραννοι πλούσιον ὃν ἄν βούλωνται παραχρῆμ’ ἐποίησαν (not *ἄν βούλοιεν)
  Tyrants make rich in a moment whomever they wish.

Demosthenes 20.15

Dramatic

In dialogues within tragedy and comedy, the first person singular aorist or present expresses an action performed by the act of speaking, like thanking someone (see performative utterance), or, according to another analysis, a state of mind.^[26] This is called tragic or dramatic aorist. The aorist is used when the action is complete in the single statement; the present when the speaker goes on to explain how or why he is acting.

• Ἀλλαντοπώλης. ἥσθην ἀπειλαῖς, ἐγέλασα ψολοκομπίαις,
  ἀπεπυδάρισα μόθωνα, περιεκόκκασα.
  Sausage-seller. I like your threats, laugh at your empty bluster,
  dance a fling, and cry cuckoo all around.

Aristophanes, The Knights 696–697: translated by William James Hickie^[27]

Unattainable wish

A wish about the past that cannot be fulfilled is expressed by the aorist indicative with the particles εἴθε or εἰ γάρ "if only" (eíthe, ei gár). This is called the aorist of unattainable wish.^[28]

• εἴθε σοι, ὦ Περίκλεις, τότε συνεγενόμην.
  If only I had been with you then, Pericles!

Xenophon, Memorabilia 1.2.46

An unattainable wish about the present uses the imperfect.^[28] A wish about the future uses the optative with or without a particle;^[29] an optative of wish may be unattainable.^[30]

Past potential

The aorist indicative (less commonly the imperfect) with the modal particle ἄν (án), Homeric κέ(ν) (ké[n]), may express past potentiality, probability, or necessity.^[31]

• τίς γὰρ ἂν ᾠήθη ταῦτα γενέσθαι;
  For who would have expected these things to happen?

Demosthenes 9.68

Iterative

The aorist indicative^[32] (also the imperfect, or past iterative in Herodotus) with ἄν án may express repeated or customary past action. This is called the iterative indicative. It is similar to the past potential, since it denotes what could have happened at a given point, but unlike the past potential, it is a statement of fact.^[33][34][35]

• ὁπότε δ’ αὖ γένοιτο κατά τινας τῶν πρόσθεν συμμαχεσαμένων, εἶπεν ἄν

But whenever he came past any of those who had fought under him before, he would say

Xenophon, Cyropaedia, 7.1.14

Unreal

The aorist or imperfect indicative with ἄν may express past unreality or counterfactuality. This is called the unreal indicative. This construction is used in the consequence of past counterfactual conditional sentences.^[36][37][38]

Potential

In the potential optative, the aorist expresses aspect, and the potential optative implies future time.^[41]