By now you can conjugate both Class Β types — Β1 αγαπάω and Β2 μπορώ — as paradigms to imitate. This page is about why they look the way they do. Every Class Β verb is a contract verb: a verb whose stem once ended in a vowel that fused with the ending, pulling the stress permanently onto the fused syllable. Understanding that one historical fact explains the end-stress, the -άω/-ώ doublets, the -άμε/-ούμε alternation, and even a cluster of everyday irregulars (λέω, ακούω, τρώω) that look like contract verbs but aren't quite. This is a consolidation page — read it once the mechanics are already in your fingers.
Where the stress comes from: an ancient contraction
In Ancient Greek a family of verbs had stems ending in -α-, -ε- or -ο- right before the personal ending. When those two vowels met, they contracted into a single long vowel — and by the rules of Greek accent, that contracted syllable carried the stress. Modern Greek inherited both the contraction and its accent:
- Β1 descends from the -άω (alpha-contract) verbs: αγαπά-ω → αγαπῶ. The stem vowel -α- fused with the ending.
- Β2 descends from the -έω (epsilon-contract) verbs: θεωρέ-ω → θεωρῶ, ποιέ-ω → ποιῶ. The stem vowel -ε- fused with the ending.
Read the Β2 endings against the ancient -έω contractions and they line up exactly: ε+ω→ώ, ε+ει→εί, ε+ε→εί(τε), ε+ο→ού. That is why μπορώ, θεωρώ and οδηγώ all end -ώ, -είς, -εί, -ούμε, -είτε, -ούν — it is the frozen output of a contraction that finished happening two thousand years ago. And because the fused syllable was always the stressed one, the accent is glued to the ending for life — the single most visible property of the whole class.
Θεωρώ ότι αυτό το έργο είναι το καλύτερό του.
theoró óti aftó to érgho íne to kalíteró tu
I consider this work to be his best. (Β2, from θεωρέ-ω)
Why Β1 has doublets but Β2 doesn't
Here is the asymmetry that trips people up. In the α-contract group (Β1), Modern Greek did something unusual: it revived the uncontracted form. Speakers went back to saying αγαπάω, μιλάω, ρωτάω — with the -α- audible again — while keeping the old contracted αγαπώ, μιλώ, ρωτώ in more formal use. That is the source of the doublets: the -άω member is the resurrected uncontracted form (colloquial), the -ώ member the inherited contracted one (formal).
The ε-contract group (Β2) never did this. There is no revived ×μποράω, ×θεωράω, ×οδηγάω, because there was never an -άω to revive — those verbs contracted from -έω, not -άω. So the rule falls out of the history: Β1 offers a choice because its uncontracted form came back; Β2 offers none because its uncontracted form was never -άω in the first place.
Άλλοι λένε «μιλάω» κι άλλοι «μιλώ» — και τα δύο σωστά.
áli léne «miláo» ki áli «miló» — ke ta dhío sostá
Some say 'miláo' and others 'miló' — both correct. (Β1 doublet)
Κανείς δεν λέει «μποράω»· το ρήμα δεν έχει τέτοιον τύπο.
kanís dhen léi «boráo»· to ríma dhen échi tétion típo
Nobody says 'boráo'; the verb has no such form. (Β2 has no -άω)
The -άμε / -ούμε alternation in the "we" form
The first-person plural is where Β1 and Β2 come closest, and it deserves its own note. Β1's everyday "we" form is -άμε (αγαπάμε, μιλάμε), but it has a more formal twin in -ούμε (αγαπούμε, μιλούμε) — the same -ούμε that Β2 uses as its only option (μπορούμε, θεωρούμε). So:
| "We" form | Β1 (αγαπάω) | Β2 (μπορώ) |
|---|---|---|
| colloquial | αγαπάμε | — (only one form) |
| formal / standard | αγαπούμε | μπορούμε |
The practical upshot: -ούμε is safe for both classes, while -άμε belongs to Β1 alone. Say αγαπάμε or αγαπούμε freely, but never ×θεωράμε or ×μπορούμε's imaginary partner ×μποράμε — Β2 has no -άμε.
Μιλάμε ή μιλούμε — ακούγονται και τα δύο καθημερινά.
miláme i milúme — akúghonde ke ta dhío kathimeriná
'miláme' or 'milúme' — you hear both every day. (Β1)
Εμείς θεωρούμε ότι είναι ακόμα πολύ νωρίς.
emís theorúme óti íne akóma polí norís
We think it's still far too early. (Β2, only -ούμε)
The near-contract irregulars: λέω, ακούω, τρώω
A small set of extremely common verbs — λέω (say), ακούω (hear/listen), τρώω (eat), plus κλαίω (cry) and φταίω (be at fault) — have a vowel-final stem and inflect almost like contract verbs, with the end-stress and the short forms, but with their own quirks. They are not Β1 or Β2; they are a class of their own.
| Person | λέω | ακούω | τρώω |
|---|---|---|---|
| εγώ | λέω | ακούω | τρώω |
| εσύ | λες | ακούς | τρως |
| αυτός/-ή/-ό | λέει | ακούει | τρώει |
| εμείς | λέμε | ακούμε | τρώμε |
| εσείς | λέτε | ακούτε | τρώτε |
| αυτοί/-ές/-ά | λένε | ακούν(ε) | τρώνε |
Notice how the "you" form loses its ending vowel entirely — λες, not ×λέεις; ακούς, not ×ακούεις; τρως, not ×τρώεις. Their real difficulty is not the present but the aorist, which is wildly suppletive (λέω → είπα, τρώω → έφαγα, ακούω → άκουσα), and that is handled in full on Vowel-final stems.
Τι λες, πάμε για έναν καφέ αργότερα;
ti les, páme ya énan kafé arghótera;
What do you say, shall we go for a coffee later?
Ακούς τι σου λέω ή κοιτάς αλλού πάλι;
akús ti su léo i kitás alú páli;
Are you listening to what I'm telling you, or looking elsewhere again?
Τρώμε όλοι μαζί το βράδυ, είναι έθιμο στο σπίτι μας.
tróme óli mazí to vrádhi, íne éthimo sto spíti mas
We all eat together in the evening, it's a custom in our house.
A quick-reference of common members
| Β1 (-άω/-ώ) | everyday 1pl | aorist |
|---|---|---|
| αγαπάω / αγαπώ | αγαπάμε | αγάπησα |
| μιλάω / μιλώ | μιλάμε | μίλησα |
| ρωτάω / ρωτώ | ρωτάμε | ρώτησα |
| περνάω / περνώ | περνάμε | πέρασα |
| γελάω / γελώ | γελάμε | γέλασα |
| πεινάω / πεινώ | πεινάμε | πείνασα |
| φυσάω / φυσώ | φυσάμε | φύσηξα |
| Β2 (-ώ/-είς) | 1pl | aorist |
|---|---|---|
| μπορώ | μπορούμε | μπόρεσα |
| οδηγώ | οδηγούμε | οδήγησα |
| θεωρώ | θεωρούμε | θεώρησα |
| καλώ | καλούμε | κάλεσα |
| ζω | ζούμε | έζησα |
The honest part: the Β1 aorist is unpredictable
Look down the Β1 aorist column and you will see the one genuinely hard thing about this class. Most Β1 verbs form the aorist in -ησα (αγάπ-ησα, μίλ-ησα, ρώτ-ησα), so that is your best default guess — but a stubborn everyday minority breaks the pattern:
- -ασα: γελάω → γέλασα, πεινάω → πείνασα, περνάω → πέρασα, ξεχνάω → ξέχασα, χαλάω → χάλασα.
- -ηξα: φυσάω → φύσηξα, τραβάω → τράβηξα.
There is no phonological rule that tells you which verb takes which — it is a lexical fact you learn with the verb, exactly the way you learn that English go has the past went. The good news is that the present is completely regular; the cost is that you must store the aorist stem separately. Flag the frequent oddballs (γέλασα, πείνασα, πέρασα, φύσηξα) early and the rest of the class will behave.
Γελάμε τώρα, αλλά χθες γελάσαμε ακόμα πιο πολύ.
yeláme tóra, alá chthes yelásame akóma pio polí
We're laughing now, but yesterday we laughed even more. (γελάω → γέλασα)
Φυσάει δυνατά σήμερα, όπως φύσηξε κι όλη τη νύχτα.
fisái dhinatá símera, ópos físikse ki óli ti níchta
It's blowing hard today, the way it did all night too. (φυσάω → φύσηξα)
A footnote: the vanished -όω verbs
Ancient Greek also had a third contract group, the -όω (omicron-contract) verbs like δηλόω. In Modern Greek almost all of them defected to Class Α by taking the ending -ώνω: δηλώνω (declare), σηκώνω (lift), πληρώνω (pay). These are ordinary γράφω-type verbs today — stem-stressed, regular — which is why the living Class Β is effectively just the α-contract (Β1) and ε-contract (Β2) heirs. If a verb ends in -ώνω, it is Class Α, not Β, no matter how "contract" it looks.
Common Mistakes
1. Regularising the "you" of λέω / ακούω. These lose the vowel: λες, ακούς — not the full contract-style ending.
❌ Με ακούεις; Η γραμμή είναι πολύ κακή.
Incorrect — the 2sg of ακούω is ακούς.
✅ Με ακούς; Η γραμμή είναι πολύ κακή.
me akús; i ghramí íne polí kakí
Can you hear me? The line is really bad.
2. Giving a Β2 verb the Β1 -άμε. θεωρώ, μπορώ and friends have only -ούμε in the "we" form.
❌ Θεωράμε ότι είναι μια καλή ιδέα.
Incorrect — Β2 has no -άμε: θεωρούμε.
✅ Θεωρούμε ότι είναι μια καλή ιδέα.
theorúme óti íne mia kalí idhéa
We think it's a good idea.
3. Defaulting every Β1 aorist to -ησα. The pattern is common but not universal; γελάω does not give ×γέλησα.
❌ Χθες γέλησα πολύ με τα αστεία του.
Incorrect — the aorist of γελάω is γέλασα, not γέλησα.
✅ Χθες γέλασα πολύ με τα αστεία του.
chthes yélasa polí me ta astía tu
Yesterday I laughed a lot at his jokes.
4. Treating an -ώνω verb as Class Β. πληρώνω is stem-stressed Class Α (πληρώνω, πληρώνεις), not ×πληρώ / ×πληρείς.
❌ Πληρείς εσύ τον λογαριασμό ή τον μοιραζόμαστε;
Incorrect — πληρώνω is Class Α: the 'you' form is πληρώνεις.
✅ Πληρώνεις εσύ τον λογαριασμό ή τον μοιραζόμαστε;
plirónis esí ton loghariazmó i ton mirazómaste;
Are you paying the bill or are we splitting it?
Key Takeaways
- Class Β verbs are contract verbs: an ancient stem-vowel fused with the ending and fixed the stress there for good.
- Β1 comes from the -άω verbs and kept a revived uncontracted form, hence its -άω/-ώ doublets; Β2 comes from the -έω verbs and has no -άω to offer.
- The "we" form: -ούμε works for both, -άμε for Β1 only — never ×θεωράμε.
- λέω, ακούω, τρώω look contract but are their own irregular vowel-stem class (λες, ακούς, τρως; suppletive aorists είπα, άκουσα, έφαγα).
- The Β1 aorist is lexical: default -ησα (μίλησα), but learn the -ασα (γέλασα, πείνασα, πέρασα) and -ηξα (φύσηξα) oddballs individually.
- The old -όω verbs became Class Α -ώνω (πληρώνω, σηκώνω) — treat any -ώνω verb as γράφω-type.
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Start learning Greek →Related Topics
- Present Tense: Class Β1 (αγαπάω/-ώ)A1 — The full present of the everyday Β1 contract verbs — αγαπάω/αγαπώ, μιλάω, ρωτάω, περπατάω, κοιτάω, ξεχνάω, περνάω — with the -άω/-ώ doublet in the 'I' and 'they' forms, the fixed -άς 'you' ending, and the crossover error ×αγαπείς that spells it as if it were Class Α.
- Present Tense: Class Β2 (μπορώ)A2 — The full present of the μπορώ type — μπορώ, μπορείς, μπορεί, μπορούμε, μπορείτε, μπορούν — plus οδηγώ, θεωρώ, καλώ and the slightly irregular ζω, with the -είς/-εί endings that never allow an -άω variant and the crossovers ×μποράω and ×μπορείς-for-Β1 that this class forbids.
- Vowel-Final Stems (ακούω, τρώω, λέω)B1 — Seven everyday verbs — λέω, τρώω, ακούω, πάω, κλαίω, καίω, φταίω — end their stem in a vowel, and that one fact reshapes the whole verb: a present with no ending vowel (λες, τρως, ακούς), a γ that reappears the moment you leave the present (έλεγα, άκουγα, κλαίγοντας, ακούγεται), and three different kinds of aorist inside one small class.