είμαι (to be) | Greek Grammar

This is a lookup card, not a lesson. The paradigms are taught on the present of είμαι and the imperfect of είμαι; what you get here is the whole verb in one glance, and — more usefully — an explicit list of the slots είμαι leaves empty, because είμαι is defective in more places than any other Greek verb.

Every form είμαι has

Slot	Forms	Gloss
Present	είμαι, είσαι, είναι, είμαστε, είστε (είσαστε), είναι	am, are, is — one είναι for both third persons
Past (imperfect)	ήμουν, ήσουν, ήταν, ήμασταν, ήσασταν, ήταν	was, were — the only past there is
Past, everyday variants	ήμουνα, ήσουνα, ήτανε, ήμαστε, ήσαστε (informal)	same meaning, looser speech
Future	θα είμαι	will be, is going to be
να-form	να είμαι	after θέλω, πρέπει, μπορεί
Command	να είσαι / να είστε; negative μην είσαι / μην είστε	be…, don't be…
Gerund	όντας(formal)	being, given that one is

Because the future and the να-form are simply θα/να plus the present, είμαι offers no aspect choice at all. Every other Greek verb makes you pick between an imperfective and a perfective stem after θα and να; here that decision never arises, which is one of the very few ways this verb is easier than a regular one.

💡

Two of the colloquial past forms are exact homophones of present forms: ήμαστε and είμαστε are both ímaste, and ήσαστε and είσαστε are both ísaste. In speech only the surrounding time words tell you whether someone said "we are" or "we were" — which is exactly why the fuller ήμασταν / ήσασταν are safer in writing.

Every form είμαι does not have

Slot	Status
Aorist	Does not exist. ήμουν covers every past, finished or not.
Perfective (dependent) stem	Does not exist. There is no ×είσω behind ×θα είσω or ×να είσω.
Perfect (έχω + -ει)	Does not exist. ×έχω είσει, ×είχα είσει are not Greek; neither is ×έχω είμαι.
Mediopassive	Does not exist — and cannot, because είμαι already is mediopassive: the -μαι / -σαι / -ται endings are its own.
Participle in -μένος	Does not exist. No passive participle is formed from this verb.
Plain imperative	Does not exist. The command slot is filled by να + the present form.

That last row is the one worth practising, because it comes up in the commonest thank-you in the language. Positive commands take να, negative ones take μην — in both cases the verb keeps its ordinary indicative shape:

Να είσαι καλά, με βοήθησες πάρα πολύ.

na íse kalá, me voíthises pára polí

Bless you — you helped me enormously.

Μην είσαι τόσο αυστηρός με τον εαυτό σου.

min íse tóso afstirós me ton eaftó su

Don't be so hard on yourself.

The gerund όντας is the one extra form, and it belongs to written and formal registers; in conversation people say επειδή ήταν… instead. It is built like any other gerund and, like all of them, never changes shape.

Όντας ξένος, δυσκολεύτηκε πολύ τον πρώτο χρόνο.

óndas ksénos, dhiskoléftike polí ton próto chróno

Being a foreigner, he had a very hard time the first year.

What είμαι takes

Complement in the nominative — Είμαι δάσκαλος, never ×Είμαι δάσκαλο. Details on the predicate nominative.
Place with σε — Είμαι στη δουλειά, Είμαστε στο σπίτι.
Age with χρονών — Είμαι σαράντα χρονών. (έχω is wrong here.)
Origin with από — see below.
Ownership with δικός + a genitive clitic — Είναι δικό μου.
Negation with δεν, always immediately before the verb.

Είμαι από τη Θεσσαλονίκη, αλλά μένω δέκα χρόνια στην Αθήνα.

íme apó ti Thesaloníki, alá méno dhéka chrónia stin Athína

I'm from Thessaloniki, but I've been living in Athens for ten years.

Αυτό το μπουφάν είναι δικό σου ή του Νίκου;

aftó to bufán íne dhikó su i tu Níku;

Is this jacket yours or Nikos's?

Phrases that live on this verb

είναι να… — "is due to, is supposed to," a scheduled or arranged event:

Είναι να πάμε στον γιατρό την Τρίτη το πρωί.

íne na páme ston yatró tin Tríti to proí

We're due to go to the doctor on Tuesday morning.

δεν είναι για… — "isn't cut out for, isn't the right thing for":

Αυτή η δουλειά δεν είναι για μένα, το κατάλαβα από την πρώτη μέρα.

aftí i dhuliá dhen íne ya ména, to katálava apó tin próti méra

This job isn't for me — I knew from the first day.

ό,τι και να 'ναι — "whatever it is, whatever the case," with είναι shortened to 'ναι after a vowel:

Ό,τι και να 'ναι, προτιμώ να το μάθω από σένα.

óti ke na 'ne, protimó na to mátho apó séna

Whatever it is, I'd rather hear it from you.

τι είναι; — a bare "what is it?", said to someone who has just interrupted you:

Τι είναι πάλι; Δεν προλαβαίνω τώρα, σε παίρνω μετά.

ti íne páli; dhen prolavéno tóra, se pérno metá

What is it now? I haven't got time — I'll call you later.

είμαι στα καλά μου — "be in one's right mind," almost always negated (informal):

Δεν είσαι στα καλά σου να οδηγείς με τέτοιο χιόνι.

dhen íse sta kalá su na odhiyís me tétio chióni

You're out of your mind driving in snow like this.

Key Takeaways

One past (ήμουν), one present, and θα/να stacked straight onto the present: no aorist, no perfective stem, no aspect choice.
No perfect, no mediopassive, no -μένος participle, no plain imperative — six empty slots, more than any other common Greek verb.
The command slot is filled by να είσαι / να είστε, negated with μην είσαι.
είναι is both "he/she/it is" and "they are"; ήταν covers both in the past.
Watch the homophones ήμαστε / είμαστε and ήσαστε / είσαστε — identical in sound, opposite in tense.

Now practice Greek

Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.

Start learning Greek →