Learn Hardcore Greek: Θα περιμένω στο αεροδρόμιο μέχρι να φτάσεις. - I will wait at the airport until you arrive.

Greek doesn’t have a separate synthetic future tense like English will wait with a special verb ending.
Instead, it uses θα + a verb form (formally the “subjunctive” form) to express future time.

So:

περιμένω = I wait / I am waiting
Θα περιμένω = I will wait / I will be waiting

You always put θα right in front of the verb:
Θα πάω, Θα φάω, Θα διαβάσω, etc.

Where are the words “I” and “you” in the Greek sentence? I only see verbs.

Greek usually drops subject pronouns (it’s a “pro‑drop” language), because the verb ending already shows who is doing the action.

In this sentence:

Θα περιμένω
- ‑ω = first person singular ending
- So it means “I will wait” without needing εγώ (“I”)
να φτάσεις
- ‑εις / ‑εις → ‑σεις here = second person singular ending
- So it means “(that) you arrive” without needing εσύ (“you”)

You can add the pronouns for emphasis or clarity, e.g.:

Εγώ θα περιμένω στο αεροδρόμιο μέχρι να φτάσεις.
I will wait at the airport until you arrive. (emphasising I)

but they are not required.

What does περιμένω mean exactly, and why is it in this form?

Περιμένω is the verb “to wait”.

Dictionary form / 1st person singular: περιμένω = I wait / I am waiting
With θα: Θα περιμένω = I will wait / I will be waiting

A few useful forms:

περιμένω — I wait / I am waiting
περίμενα — I waited
περίμενε! — Wait! (imperative, to one person)

In everyday speech, θα περιμένω usually means “I’ll be waiting (for some time)”, i.e. a continuous future action.

Could this also be Θα σε περιμένω στο αεροδρόμιο? What’s the difference?

Yes, that’s also correct, and it slightly changes the focus.

Θα περιμένω στο αεροδρόμιο
Literally: I will wait at the airport.
It does not say explicitly whom you are waiting for (though the context may make it clear).
Θα σε περιμένω στο αεροδρόμιο
Literally: I will wait for you at the airport.
The pronoun σε makes it explicit that you are the object of “wait”.

With the full sentence:

Θα περιμένω στο αεροδρόμιο μέχρι να φτάσεις.
I will wait at the airport until you arrive. (We infer it’s “for you”.)
Θα σε περιμένω στο αεροδρόμιο μέχρι να φτάσεις.
I will wait for you at the airport until you arrive. (More explicit.)

What does μέχρι να mean, and why do we need να there?

Μέχρι by itself means “until / up to”.

With a noun:
- μέχρι τις τρεις = until three o’clock
- μέχρι το σπίτι = up to / as far as the house

When μέχρι is followed by a clause with a verb, Greek normally uses μέχρι να + verb for future or unknown events:

Θα περιμένω μέχρι να φτάσεις.
I will wait until you arrive.

Here:

μέχρι = until
να φτάσεις = (that) you arrive

You cannot say ✗ μέχρι φτάσεις in standard Modern Greek; you need να:

μέχρι να φτάσεις ✅
μέχρι φτάσεις ❌

What tense or form is φτάσεις? How is it different from φτάνεις or θα φτάσεις?

All three come from the verb φτάνω = to arrive.

φτάνεις — present, 2nd person singular
- you arrive / you are arriving
θα φτάσεις — future, 2nd person singular
- you will arrive
(να) φτάσεις — aorist subjunctive, 2nd person singular
- used after να, often translated as “(that) you arrive” or “you arrive (once / as an event)”

In μέχρι να φτάσεις:

The να marks the subjunctive mood.
The aorist form φτάσεις focuses on the completed event of your arrival (the moment you get there).

So μέχρι να φτάσεις = until you (finally) arrive.

Why is it μέχρι να φτάσεις and not μέχρι να φτάνεις?

Greek chooses between two aspects in the subjunctive:

Aorist subjunctive (single, completed event): να φτάσεις
Imperfective subjunctive (ongoing / repeated action): να φτάνεις

With μέχρι (να), you almost always talk about a point of completion — the moment when something is finished or achieved. So you use the aorist:

Θα περιμένω μέχρι να φτάσεις.
I will wait until you arrive (once).

Sentences like ✗ μέχρι να φτάνεις are not natural in this context.
You use να φτάνεις in other patterns, e.g.:

Μπορεί να φτάνεις αργά κάθε μέρα.
You may be arriving late every day. (repeated/ongoing pattern)

Why can’t we just say μέχρι θα φτάσεις for “until you will arrive”?

Because in Greek:

Θα + verb is a full future clause on its own.
Μέχρι when followed by a verb clause about the future doesn’t take θα; it takes να + subjunctive instead.

So:

Θα περιμένω μέχρι να φτάσεις. ✅
Θα περιμένω μέχρι θα φτάσεις. ❌ (ungrammatical)

Think of it like this:

English: until you arrive / until you have arrived
Greek: μέχρι να φτάσεις

The future meaning is already understood from the context (Θα περιμένω…).

What does στο mean in στο αεροδρόμιο? Why not just σε το αεροδρόμιο?

Στο is a contraction of:

σε = at / in / to
το = the (neuter singular article)

So:

σε + το αεροδρόμιο → στο αεροδρόμιο

You do the same with other genders and numbers:

σε + τον δρόμο → στον δρόμο (in / on the street)
σε + την πόλη → στην πόλη (in the city)
σε + τα σπίτια → στα σπίτια (at the houses)

In everyday language, you almost always use the contracted form (στο, στον, στην, στα).

What exactly does αεροδρόμιο mean, and what gender is it?

Αεροδρόμιο means “airport”.

It is a neuter noun.
Its definite article is το: το αεροδρόμιο = the airport.

So στο αεροδρόμιο literally is:

σε + το αεροδρόμιο → στο αεροδρόμιο
at / in the airport

Can we change the word order, like Θα περιμένω μέχρι να φτάσεις στο αεροδρόμιο? Does that mean the same thing?

You can say:

Θα περιμένω μέχρι να φτάσεις στο αεροδρόμιο.

But the meaning changes slightly:

Θα περιμένω στο αεροδρόμιο μέχρι να φτάσεις.
I will wait at the airport until you arrive (the place is known from context; probably at that same airport).
Θα περιμένω μέχρι να φτάσεις στο αεροδρόμιο.
I will wait until you arrive at the airport (specifically until your arrival at the airport; it doesn’t say where I am waiting).

So moving στο αεροδρόμιο inside the μέχρι να clause attaches it to φτάσεις (“you arrive at the airport”), not to περιμένω (“I wait at the airport”).

Could I also say Περιμένω στο αεροδρόμιο μέχρι να φτάσεις without θα?

Yes, that is correct Greek, and it’s slightly different in meaning:

Θα περιμένω στο αεροδρόμιο μέχρι να φτάσεις.
I will wait at the airport until you arrive.
→ Future plan / promise.
Περιμένω στο αεροδρόμιο μέχρι να φτάσεις.
I am waiting at the airport until you arrive.
→ Either:
- describing what is happening right now, or
- describing a fixed plan, similar to English “I’m waiting at the airport until you arrive tomorrow.”

So with θα = future; without θα = present (which can sometimes refer to the near future, like in English).

How do I pronounce Θα περιμένω στο αεροδρόμιο μέχρι να φτάσεις?

Approximate pronunciation (stress in bold):

Θα περιμένω στο αεροδρόμιο μέχρι να φτάσεις

Broken down:

Θα → “tha” (θ like English th in think)
περιμένω → pe-ri-ME-no
στο → sto
αεροδρόμιο → a-e-ro-DRO-mio (the αι here is actually ε sound? no; there is only αε, two separate vowels; pronounce both quickly)
μέχρι → ME-chri (χ like a soft German ch in Bach)
να → na
φτάσεις → FTA-sis (the initial cluster φτ as in fta; stress on φτά)

All vowels are short and clear, and the stressed syllables are as marked in bold.

Is there any difference between μέχρι and μέχρι να in meaning?

Yes, they are used in different structures:

μέχρι + noun / time expression
- Θα περιμένω μέχρι τις πέντε.
  I will wait until five o’clock.
- Περπάτησα μέχρι το χωριό.
  I walked up to the village.
μέχρι να + verb (subjunctive)
- Θα περιμένω μέχρι να φτάσεις.
  I will wait until you arrive.
- Δούλεψε μέχρι να τελειώσει.
  He/she worked until he/she finished.

So:

μέχρι
- noun/phrase
μέχρι να
- verb (future/unknown event, subjunctive form)

Could I use μέχρι που instead of μέχρι να φτάσεις?

Colloquially, yes, you may hear:

Θα περιμένω στο αεροδρόμιο μέχρι που θα φτάσεις. (often with θα)
or μέχρι που να φτάσεις.

However, in standard, careful Greek, for this kind of future event the most natural and neutral form is:

μέχρι να φτάσεις

So for learning purposes, it’s best to stick to:

μέχρι + noun
μέχρι να + verb (subjunctive)

and treat μέχρι που as a more colloquial, regional, or stylistic variant you might discover later.