Aorist: Class Α

The aorist (αόριστος) is Greek's perfective past: it presents an event or a finite series as one bounded whole — I wrote, I ran, I opened. This page builds it for Class Α verbs, the first conjugation: the ones stressed on the stem, like γράφω (write), παίζω (play), τρέχω (run) and ανοίγω (open). (The stressed Class Β verbs in -άω/-ώ — αγαπώ → αγάπησα, μιλώ → μίλησα — build their aorist on the -ησα pattern and have their own page.) The recipe has three ingredients — an augment, the perfective stem, and a set of past endings — but here is the good news up front: two of those three you already know cold, and the whole tense turns on one change.

The paradigm: γράφω → έγραψα

Take γράφω ("I write"). Its perfective stem is γραψ- (φ + σ merge into ψ), and onto that we hang the past endings:

The endings themselves are -α, -ες, -ε, -αμε, -ατε, -αν. (Colloquially you'll also hear a longer 3rd-plural in -ανε — έγραψανε / γράψανε (informal) — but the standard written form is -αν.)

The one thing that changes: the stem

Here is the insight that makes the aorist easy. Those endings — -α, -ες, -ε, -αμε, -ατε, -αν — and the augment behaviour are exactly the imperfect's. Put the two pasts of γράφω side by side:

The two columns differ in one letter: the imperfect keeps the imperfective stem γράφ-, the aorist swaps in the perfective stem γράψ-. Same augment, same endings, same stress. This is why the aorist is far less work than it looks: you are not learning a new tense machine, you are feeding a new stem into the machine you already own. Everything hard about the aorist is really about building that stem — and that is a job you do once, in the Aspect section. What the swap means — was writing vs. wrote — is the whole subject of aspect in the past.

The perfective stem in action

In the regular sigmatic Class Α pattern taught here, the perfective stem adds -σ- to the lexical base. When that base ends in a consonant, the -σ- fuses with it, which is where these aorists get their variety. Class Α also contains verbs with lexical or suppletive perfective stems, so this is a productive pattern, not a rule you can apply blindly to every verb.

Notice παίζω → έπαιξα: a -ζω verb going to -ξα, not the -σα you might expect from the letter ζ. That split is one of the trickier corners of the system, and it — along with every other consonant merge — gets its own drilling on the aorist consonant merges page. Vowel-final bases such as ακούω → άκουσα join the -σ- without a consonant merge and are collected on the vowel-stem aorists page.

The augment: why έγραψα but γράψαμε

Look back at the paradigm and you'll see a little ε- appear and disappear: έγραψα, έγραψες, έγραψε, but plain γράψαμε, γράψατε — then έγραψαν again. That ε- is the augment, and it is not decoration: Greek past-tense stress wants to sit on the third syllable from the end, and short forms don't have three syllables to offer. Γραψα would be only two syllables, with nowhere for the accent to land — so the augment steps in to provide the missing syllable: έ-γρα-ψα. In γρά-ψα-με the ending already supplies a third syllable, so the stress falls naturally on γρά- and the augment is not needed.

The augment carries the stress in the singular and the 3rd plural (έγραψα, έγραψες, έγραψε, έγραψαν) and vanishes in the 1st and 2nd plural (γράψαμε, γράψατε). This is identical to the imperfect. The full story of when the augment appears, drops, and even hides inside compound verbs is on the augment page; the pure accent rule lives on accent in the aorist.

What the aorist says

The aorist presents a situation from outside, as a bounded whole. That whole is often one completed event, but it can also be a closed duration or finite repeated series. English usually renders it with the plain simple past:

Set that against the imperfect έγραφα ("I was writing / I used to write"), which keeps the event open and unbounded. Choosing between the two is the central skill of Greek past narration; it has its own home on using the aorist and the imperfect-vs-aorist comparison. (You'll have spotted είδα above: a handful of everyday verbs — βλέπω → είδα, λέω → είπα, τρώω → έφαγα, παίρνω → πήρα — build their aorist from a completely different root. These suppletive aorists are collected on irregular and suppletive aorists.)

Common Mistakes

1. Keeping the augment (and its stress) in the plural. The 1st and 2nd plural have no augment, and stressing the aorist four syllables back is impossible in Greek — ×έπαιξαμε is not a word.

2. Assuming every Class Α verb builds its perfective stem mechanically. The regular merges are productive, but other Class Α verbs supply a lexical perfective stem that must be learned with the present.

3. Treating the two stems as interchangeable without a viewpoint change. A situation that later ended may still be presented internally; use the perfective stem when you package it as a bounded whole.

Key Takeaways

• The Class Α aorist = augment + perfective stem + past endings (-α, -ες, -ε, -αμε, -ατε, -αν).
• Those endings and the augment are identical to the imperfect's — the only difference between έγραφα and έγραψα is the stem (imperfective γράφ- vs. perfective γράψ-).
• In the regular sigmatic pattern, the perfective base takes -σ-, which merges with a final consonant: γράφω → έγραψα, τρέχω → έτρεξα, ανοίγω → άνοιξα. Other Class Α verbs have lexical perfective stems; the regular merges are drilled on the consonant-merges page.
• The augment ε- appears only where the form needs a third syllable for the stress: έγραψα, έγραψαν — but γράψαμε, γράψατε.
• The aorist frames a situation as a bounded whole (Χθες έγραψα ένα γράμμα); it does not inherently mean "once," because a finite series can also be packaged perfectively. That choice is covered in using the aorist.