Irregular and Suppletive Aorists

Greek's aorist is remarkably regular — meet the consonant merges once and you can build the past of thousands of verbs. But a small set of verbs refuses the machinery and switches to a different root in the aorist. βλέπω ("see") becomes είδα; τρώω ("eat") becomes έφαγα; the present and the past share no letters. This is suppletion — the same thing English does in go → went or am → was — and there is no rule to derive it. You memorise it.

Here is the good news that makes the effort worth it: these are the highest-frequency verbs in the language. See, say, go, come, take, find, give, eat, drink, stay — you cannot get through three sentences of Greek without them. So the dozen forms below are not obscure exceptions to file away; they are the most-used past tenses you will ever produce, and the payoff for learning them is immediate. Grouping them by shape makes the load far lighter than it first looks.

The core dozen

They may look like twelve separate headaches, but they fall into three shapes.

Group 1: the stressed ει-/η- augment (είδα, είπα, ήρθα, ήπια)

Four very common verbs — mostly of perceiving and speaking — build the aorist on a stressed ει- or η- at the front. This front vowel is the accent, and it stays put across the whole tense.

Only the front stem is irregular; the person-endings (-α, -ες, -ε, -αμε, -ατε, -αν) are the ordinary aorist set. And crucially the stress does not wander — it is welded to that ει-/η-.

Group 2: the -ήκα shape (βρήκα, μπήκα, βγήκα) — and πήγα

Three of these build the aorist on a stressed -η- plus -κα: βρήκα, μπήκα, βγήκα — learn the frame _ήκα and only the opening consonant cluster changes. Two of them (μπαίνω/βγαίνω) are motion verbs that pair naturally. πήγα rides along in the same group because it sounds like them and behaves like them, but note its spelling: it is πή-γα with a γ, not ×πήκα — the odd one out of the four.

Group 3: the stem-changers (έφαγα, έδωσα, έμεινα, πήρα)

The last four take the ordinary augment έ- (or, for παίρνω, a stressed πή-) but on a rebuilt stem that you cannot predict from the present: τρώω → έφαγα, δίνω → έδωσα, μένω → έμεινα, παίρνω → πήρα.

The imperfect stays regular — only the aorist is odd

Here is a saving grace. These verbs are irregular only in the aorist. Their imperfect is built normally, on the present stem: βλέπω → έβλεπα, λέω → έλεγα, τρώω → έτρωγα, πηγαίνω → πήγαινα, παίρνω → έπαιρνα, δίνω → έδινα. So you never have to learn a second oddity — the strangeness is confined to the single completed past.

This contrast is also the meaning contrast: έβλεπα τηλεόραση is I was watching TV (background), while είδα μια ταινία is I watched/saw a film (one finished event). The perfective irregular stems page shows the same roots feeding the future and subjunctive (θα δω, να πω, θα φάω).

Common Mistakes

1. Regularizing βλέπω. There is no ×έβλεψα for the aorist; the completed past is είδα.

2. Building a regular aorist for τρώω. No ×έτρωσα or ×τρώησα; it is έφαγα.

3. Regularizing πίνω. The aorist is ήπια, not ×έπια.

4. Using the imperfect for a single completed act. έδινε is was giving / used to give; a one-off, finished giving is έδωσε.

Key Takeaways

• A dozen top-frequency verbs are suppletive in the aorist — the past switches root, and no rule derives it. You simply learn them.
• They cluster in three shapes: the stressed ει-/η- set (είδα, είπα, ήρθα, ήπια), the _ήκα set (πήγα, βρήκα, μπήκα, βγήκα), and the stem-changers (έφαγα, έδωσα, έμεινα, πήρα).
• The irregularity is only in the aorist: the imperfect is built normally on the present stem (έβλεπα, έλεγα, έδινα) — which also carries the was ‑ing meaning.
• ήρθα is everyday speech; ήλθα is its (formal) / (literary) twin.
• Because these verbs are so common, learning their aorists is the single highest-value move in the whole past tense.