Every Greek verb has two past tenses, and choosing between them is the single most frequent aspect decision you will make. The imperfect is the imperfective past — was doing, used to do — and the aorist is the perfective past — did, and it's done. Same event, two camera angles, and Greek makes you pick every time you tell a story. The good news for an English or Spanish speaker: this is the one battleground your first language already prepared you for.
Two pasts, one verb
Both pasts are built from the same verb but on different stems. The imperfect uses the imperfective stem (γράφ-), the aorist the perfective stem (γράψ-):
| Imperfect (imperfective past) | Aorist (perfective past) | |
|---|---|---|
| Form | έγραφα | έγραψα |
| Stem | γράφ- (imperfective) | γράψ- (perfective) |
| View | ongoing / repeated / habitual | a single bounded whole |
| English | was writing / used to write | wrote |
How each is actually built — the endings, the augment — is on the imperfect and aorist pages. Here we care only about which one to reach for.
The signature pattern: background cut by an event
The clearest place to feel the difference is a sentence with two past actions: a longer one going on, and a sudden one that breaks in. The ongoing background takes the imperfect; the interrupting event takes the aorist.
Διάβαζα όταν χτύπησε το τηλέφωνο.
dhiávaza ótan chtípise to tiléfono
I was reading when the phone rang. (background: imperfect / event: aorist)
The reading (διάβαζα) is the stretch you were inside of; the ringing (χτύπησε) is a single point that lands inside it. Swap the aspects and the meaning breaks — you cannot use the aorist διάβασα for the frame here, because a frame has no full stop. This one template covers an enormous amount of everyday narration:
Περπατούσα στον δρόμο όταν με φώναξε ένας παλιός φίλος.
perpatúsa ston dhrómo ótan me fónakse énas paliós fílos
I was walking down the street when an old friend called out to me.
Ενώ μαγείρευα, κάηκε το φαγητό στον φούρνο.
enó mayíreva, káike to fayitó ston fúrno
While I was cooking, the food burnt in the oven.
Habit vs single event
The second big split: something that used to happen (repeated over a period) is imperfect; something that happened once is aorist. English marks the habit with used to / would, and Greek matches it with the imperfect.
Όταν ήμουν φοιτητής, έμενα σε ένα μικρό διαμέρισμα στο κέντρο.
ótan ímun fititís, émena se éna mikró dhiamérizma sto kéndro
When I was a student, I lived in a small flat in the centre. (a standing situation → imperfect)
Πέρσι μετακόμισα σε μεγαλύτερο σπίτι με κήπο.
pérsi metakómisa se meghalítero spíti me kípo
Last year I moved to a bigger house with a garden. (one event → aorist)
Κάθε Κυριακή τρώγαμε στης γιαγιάς όλη η οικογένεια.
káthe kiriakí tróghame stis yayás óli i ikoyénia
Every Sunday the whole family used to eat at grandma's. (repeated → imperfect)
Εκείνη την Κυριακή φάγαμε σε μια ταβέρνα δίπλα στη θάλασσα.
ekíni tin kiriakí fághame se mia tavérna dhípla sti thálasa
That particular Sunday we ate at a taverna by the sea. (one occasion → aorist)
Description and states: the imperfect
Because states and descriptions have no natural endpoint — the weather, how someone looked, what you knew or felt — they take the imperfect when you paint the backdrop of a past scene. The events that then happen against that backdrop are aorist.
Έβρεχε και έκανε κρύο, γι' αυτό μείναμε τελικά μέσα.
évreche ke ékane krío, yaftó míname teliká mésa
It was raining and it was cold, so in the end we stayed in. (backdrop: imperfect / decision: aorist)
Δεν ήξερα ότι είχες γενέθλια, συγγνώμη που δεν σε πήρα!
dhen íksera óti íches yenéthlia, sighnómi pu dhen se píra
I didn't know it was your birthday, sorry I didn't call! (ongoing state of knowledge → imperfect)
The English and Spanish bridges
For an English speaker the rough map is reliable as a starting point:
- was / were + -ing → imperfect (Διάβαζα)
- used to / would (habit) → imperfect (έμενα)
- simple past (one finished event) → aorist (μετακόμισα)
But the English simple past is a false friend, because it also covers habits ("I lived there for years" is a state → imperfect) and it lets the -ing form attach even to bounded wholes ("I read the whole book last night" → aorist, despite the -ing). So you cannot read the tense straight off English. Spanish, on the other hand, splits its past almost exactly where Greek does: the imperfecto (leía, vivía) is the Greek imperfect, and the pretérito (leyó, se mudó) is the Greek aorist. If you have that distinction already, transfer it wholesale — the fit is near-perfect.
The honest grey zone
Not every past is a clean call, and pretending so would mislead you. A single durative event — "I worked all day yesterday" — can be told either way, with a real shade of difference. The aorist frames the whole day as one bounded block (δούλεψα όλη μέρα — and that was my day); the imperfect puts you inside the stretch (δούλευα όλη μέρα — the day was one long working). Both are natural Greek. Native speakers themselves vary here, and the full decision procedure — including these judgment calls — lives on the choosing the right aspect guide.
Χθες δούλεψα δώδεκα ώρες και έπεσα ξερός στο κρεβάτι.
chthes dhúlepsa dhódheka óres ke épesa kserós sto kreváti
Yesterday I worked twelve hours and collapsed into bed. (the day as one bounded block → aorist)
Common Mistakes
1. Using the aorist for the ongoing background. The frame an event interrupts must be imperfect.
❌ Όταν με πήρες τηλέφωνο, οδήγησα προς τη δουλειά.
Incorrect — the background action needs the imperfect: οδηγούσα.
✅ Όταν με πήρες τηλέφωνο, οδηγούσα προς τη δουλειά.
ótan me píres tiléfono, odhighúsa pros ti dhuliá
When you called me, I was driving to work.
2. Using the imperfect for a single, punctual event. μόλις ("as soon as") marks one completed point, so it takes the aorist.
❌ Μόλις έφτανα σπίτι, πήρα τηλέφωνο τη μαμά μου.
Incorrect — a single completed arrival needs the aorist: έφτασα.
✅ Μόλις έφτασα σπίτι, πήρα τηλέφωνο τη μαμά μου.
mólis éftasa spíti, píra tiléfono ti mamá mu
As soon as I got home, I called my mum.
3. Using the aorist for a repeated past habit. "Every Saturday" makes the action recurrent, so it needs the imperfect.
❌ Κάθε Σάββατο ξύπνησα αργά και δεν έκανα τίποτα.
Incorrect — a weekly habit is imperfect: ξυπνούσα.
✅ Κάθε Σάββατο ξυπνούσα αργά και δεν έκανα τίποτα.
káthe Sávato ksipnúsa arghá ke dhen ékana típota
Every Saturday I used to wake up late and do nothing.
4. Copying the English -ing onto a bounded whole. "The whole book" is a completed result, so Greek prefers the aorist even where English says was reading.
❌ Χθες το βράδυ διάβαζα όλο το βιβλίο μονορούφι.
Incorrect — a whole book finished in one go is a bounded event: διάβασα.
✅ Χθες το βράδυ διάβασα όλο το βιβλίο μονορούφι.
chthes to vrádhi dhiávasa ólo to vivlío monorúfi
Last night I read the whole book in one sitting.
Key Takeaways
- Greek has two past tenses per verb: the imperfect (imperfective — έγραφα, was writing / used to write) and the aorist (perfective — έγραψα, wrote).
- Use the imperfect for the background, habits, and descriptions/states; use the aorist for a single completed event and for the action that interrupts a background.
- The signature template is a long imperfect frame cut by a sudden aorist: Διάβαζα όταν χτύπησε το τηλέφωνο.
- The English map (was -ing / used to → imperfect; did → aorist) is a starting point but leaks; Spanish's imperfecto/pretérito is a near-exact match — transfer it directly.
- Durative single events (worked all day) can go either way with a shade of difference; the choosing guide handles the grey zone.
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Start learning Greek →Related Topics
- Using the ImperfectA2 — The four jobs the imperfect (παρατατικός) does — the ongoing background of a past scene, a repeated or habitual past, the description of past states and settings, and a softened, polite request — each set against the single-event aorist and mapped onto English 'was doing / used to do / would do'.
- Using the AoristA2 — The aorist is Greek's default past tense: single finished actions (πήγα, είδα), events chained in a narrative (μπήκε, κάθισε, παρήγγειλε), actions with a result (έμαθα ελληνικά), and time-bounded stretches (έμεινα δύο χρόνια) — the tense that most often lines up with the English simple past, and how it splits work with the imperfect.
- Choosing the Right AspectB1 — The one page to bookmark: a single decision procedure for picking imperfective vs perfective in any tense or mood. Ask whether the action is one bounded event (→ perfective) or ongoing/repeated/background (→ imperfective), read the signal words, and work through ten real decisions across the past, future, subjunctive and imperative.