Look at these two past tenses: έγραψα (I wrote) and αγόρασα (I bought). The first has a mysterious extra ε- stuck on the front that isn't in the present γράφω; the second doesn't. This little ε- is called the augment (αύξηση), and English speakers usually mis-file it as "the Greek past-tense prefix." It isn't quite that. Understanding what it really does — carry the stress — is the key to knowing when it shows up and when it vanishes.
The core mechanism: a home for the stress
Greek past tenses (the imperfect and the aorist) want their stress on the antepenult — the third syllable from the end. That is a general fact about verb stress, explored on verb accentuation. But a short, two-syllable verb like γράφω simply doesn't have a third syllable to put the stress on. So the past tense grows one: it prefixes a stressed ε- to act as the host.
| Present | Aorist | Why the ε-? |
|---|---|---|
| γράφω | έγραψα | 2 syllables — needs a 3rd to carry the stress |
| παίζω | έπαιξα | same |
| τρέχω | έτρεξα | same |
| κρίνω | έκρινα | same |
Χθες έπαιξα ποδόσφαιρο με τα παιδιά στην αυλή.
chthes épeksa podhósfero me ta pedhiá stin avlí
Yesterday I played football with the kids in the yard.
Έτρεξα να προλάβω το λεωφορείο και το έχασα.
étreksa na prolávo to leoforío ke to échasa
I ran to catch the bus and missed it.
Why it disappears: the stem is already long enough
Now the other half of the rule. A verb of three or more syllables already has an antepenult of its own, so the past tense has somewhere to put the stress without any help — and the augment simply doesn't appear.
| Present | Aorist | Augment? |
|---|---|---|
| αγοράζω | αγόρασα | no — stress lands on -γό- |
| διαβάζω | διάβασα | no — stress lands on -ά- |
| δουλεύω | δούλεψα | no — stress lands on -ού- |
| ταξιδεύω | ταξίδεψα | no — stress lands on -ξί- |
This is why ×εαγόρασα is flatly wrong: the verb already had a third-from-last syllable, so there was never any job for the augment to do.
Αγόρασα καινούριο κινητό την περασμένη βδομάδα.
aghórasa kenúrio kinitó tin perazméni vdhomádha
I bought a new phone last week.
Διάβασα όλο το βιβλίο σε μία μέρα.
dhiávasa ólo to vivlío se mía méra
I read the whole book in a single day.
The same verb, augment on and off
The clearest proof that the augment is about stress, not tense, is that a single verb takes it in some past forms and drops it in others. In γράφω, the singular and third-person-plural forms are short enough to need it (έγραψα, έγραψες, έγραψε, έγραψαν), but the first and second person plural add an ending that already supplies the extra syllable — so the ε- vanishes: γράψαμε, γράψατε.
Χθες γράψαμε ένα γράμμα στον παππού για τα γενέθλιά του.
chthes ghrápsame éna ghráma ston papú ya ta yenéthliá tu
Yesterday we wrote a letter to grandpa for his birthday.
Έγραψα το όνομά μου στη λίστα των εθελοντών.
éghrapsa to ónomá mu sti lísta ton ethelondón
I wrote my name on the volunteers' list.
In casual speech you'll even hear the augment dropped from the singular where it would be unstressed in a longer compound — but for the everyday short verbs above, keeping it in writing is the standard (formal and informal).
The η- augment: a learned leftover
A handful of very common verbs take η- instead of ε-. These are inherited from an older layer of the language and are simply memorised. The big four you meet immediately:
| Present | Past | Meaning |
|---|---|---|
| θέλω | ήθελα | I wanted |
| ξέρω | ήξερα | I knew |
| πίνω | ήπια | I drank |
| έρχομαι | ήρθα | I came |
είχα does not belong on this list, however tempting it looks. The past of έχω is written ει-, not η-, and the two are identical to the ear — both are [i] — which is exactly why learners file it here and invent an "η- augment" for it. There is no η in it: είχα is built on the stem ειχ- and is learned whole, like ήμουν. See the imperfect of έχω.
Two of the four above are technically imperfects and two are aorists: θέλω and ξέρω have no separate everyday aorist, so ήθελα and ήξερα cover the whole past, while ήπια and ήρθα are genuine perfective aorists. What groups them is the η-, not their aspect.
Ήθελα να σου τηλεφωνήσω, αλλά το ξέχασα εντελώς.
íthela na su tilefoníso, alá to kséchasa endelós
I wanted to call you, but I completely forgot.
Δεν ήξερα ότι ήσουν κι εσύ εδώ.
dhen íksera óti ísun ki esí edhó
I didn't know you were here too.
The internal augment in compound verbs
Verbs built from a preposition + a stem (like υπο-γράφω, "sign", literally "under-write") put the augment inside, between the prefix and the stem, not at the very front: υπογράφω → υπέγραψα. This is the internal augment, and it belongs to the more formal, learned register.
Ο δικηγόρος υπέγραψε τα χαρτιά χωρίς να τα διαβάσει.
o dhikighóros ipéghrapse ta chartiá chorís na ta dhiavási
The lawyer signed the papers without reading them.
The internal augment and the η- augment each have their own detailed pages — see the aorist augment, the imperfect augment, and the internal augment. This page is only the overview.
Why English speakers find this odd
English has nothing like the augment. Our past tense either changes the vowel inside the word (sing → sang) or adds -ed at the end (walk → walked) — never a stressed syllable at the front that appears and disappears depending on the word's length. The trick is to stop hunting for a meaning in the ε-: it carries no meaning of its own, only the stress.
Common Mistakes
1. Adding an augment to a long verb. If the stem already reaches the antepenult, there's no augment.
❌ Χθες εαγόρασα ένα καινούριο ποδήλατο.
Incorrect — αγοράζω is long enough; the aorist is αγόρασα, no augment.
✅ Χθες αγόρασα ένα καινούριο ποδήλατο.
chthes aghórasa éna kenúrio podhílato
Yesterday I bought a new bike.
2. Dropping the augment from a short singular past. έγραψα needs its ε-; γράψα is not a word.
❌ Γράψα ένα μεγάλο μήνυμα και το έσβησα.
Incorrect — the singular aorist keeps the augment: έγραψα.
✅ Έγραψα ένα μεγάλο μήνυμα και το έσβησα.
éghrapsa éna meghálo mínima ke to ézvisa
I wrote a long message and then deleted it.
3. Using ε- where the verb wants η-. The learned η- verbs must be memorised.
❌ Εθελα να έρθω, αλλά αρρώστησα.
Incorrect — θέλω takes the η- augment: ήθελα.
✅ Ήθελα να έρθω, αλλά αρρώστησα.
íthela na értho, alá aróstisa
I wanted to come, but I got sick.
Key Takeaways
- The augment ε- is a stress-carrier, not a meaning-bearing past marker.
- Short verbs grow it to host the antepenultimate stress (έγραψα); longer verbs don't need it (αγόρασα, διάβασα).
- The same verb can have it (έγραψα) and lose it (γράψαμε) depending on how long the form is.
- A memorised set takes η- instead (ήθελα, ήξερα, ήπια, ήρθα) — but not είχα, which is spelled ει- and only sounds like the others; compounds put an internal augment inside (υπέγραψα).
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Start learning Greek →Related Topics
- The Augment in the AoristA2 — The stressed ε- that appears on έγραψα, έπαιξα and έτρεξα but vanishes in γράψαμε and on longer verbs like αγόρασα and αγάπησα — the aorist augment works exactly like the imperfect one; only the stem differs.
- The Augment in the ImperfectB1 — Why the stressed ε- appears on έγραφα and έπαιζα but vanishes in γράφαμε and παίζατε — the augment's real job of hosting the antepenultimate stress, plus its behaviour on compound verbs and its absence on Class Β.
- Internal and η- AugmentB2 — Why the past of a compound verb lands the augment inside the word (κατάλαβα, ανέβηκα, υπέγραψα) and why a handful of verbs use η- instead of ε- (ήθελα, ήπια, ήρθα) — the two places where the augment, not the stem, is what makes a past tense look irregular.