Learn Hardcore Greek: Μπορώ να περιμένω δύο λεπτά, αλλά μετά πρέπει να φύγω. - I can wait two minutes, but then I have to leave.

Modern Greek doesn’t generally use a true infinitive the way English does. Instead, it uses να + a finite verb form (often called the subjunctive construction).
So Μπορώ να περιμένω literally works like “I can that I wait,” but idiomatically it’s just “I can wait / I’m able to wait.”

What exactly is να doing here?

να is a particle that introduces the subjunctive-style verb form. After verbs like μπορώ (can), πρέπει (must), θέλω (want), μπορεί (it’s possible), etc., Greek typically uses να before the next verb:

Μπορώ να περιμένω = I can wait
Πρέπει να φύγω = I must leave

Why is it περιμένω (present) and not a different tense?

After να, Greek uses a verb form that looks like the present tense but functions as a subjunctive form. In να περιμένω, the action is viewed as something you are able/willing to do (not a completed fact yet).
Here it also matches the idea of “I can wait (for a short time).”

Could I say Μπορώ να περιμένω για δύο λεπτά? What’s the difference?

Yes, you can. Both are common:

να περιμένω δύο λεπτά = wait two minutes (duration expressed directly)
να περιμένω για δύο λεπτά = wait for two minutes (the για makes the “for” explicit)

Often χωρίς για sounds a bit more direct/neutral; με για can feel slightly more explicit.

Why is δύο λεπτά in that form? Is it plural? What case is it?

λεπτό = minute (singular)
λεπτά = minutes (plural)

With numbers like δύο (two), Greek uses the plural form, and in this kind of “duration” expression it appears in the accusative form—which for neuter nouns like λεπτό looks the same as the nominative plural (λεπτά).

What does αλλά μετά mean here, and where does μετά usually go?

αλλά = but
μετά = then/afterwards

αλλά μετά πρέπει να φύγω is a very natural sequence: “but then I have to leave.”
μετά is flexible and can move a bit for emphasis:

… αλλά μετά πρέπει να φύγω. (very common)
… αλλά πρέπει μετά να φύγω. (also possible)

Why is it πρέπει να φύγω and not something like “I must to leave”?

Greek expresses “must” with πρέπει + να + verb:

Πρέπει να φύγω = I must leave / I have to go

πρέπει itself doesn’t change for person (it stays πρέπει), and the person is shown by the verb after να (φύγω = I leave).

Why is φύγω not φεύγω?

Greek often distinguishes between:

φεύγω (imperfective) = leaving as a process / generally “I leave / I’m leaving”
φύγω (perfective) = leaving as a single, complete action “I leave (once) / I’ll head off”

After πρέπει να…, να φύγω is very common because it frames leaving as one decisive action you must do after waiting.

Is there a difference between πρέπει να φύγω and πρέπει να πάω?

Yes:

πρέπει να φύγω = I must leave (emphasis on departing from here)
πρέπει να πάω = I must go (emphasis on going somewhere / moving on)

Both can translate as “I have to go,” but φύγω is often the natural choice when you’re ending a conversation or exiting a place.

Why is there a comma in Μπορώ να περιμένω δύο λεπτά, αλλά…? Is it required?

It’s standard punctuation because you’re joining two independent parts with αλλά (“but”). In Greek, as in English, a comma before αλλά is very common:

…, αλλά μετά πρέπει να φύγω.

You may see it omitted in very informal writing, but the comma is recommended.

Can the subject εγώ be added? Would it change the meaning?

Yes, you can say:

(Εγώ) μπορώ να περιμένω δύο λεπτά…

Greek often drops subject pronouns because the verb ending already shows the person. Adding εγώ usually adds emphasis/contrast, like “I can wait (but someone else maybe can’t).”

How would I make this more polite or softer in tone?

A few natural ways:

Add παρακαλώ: Μπορώ να περιμένω δύο λεπτά, αλλά μετά πρέπει να φύγω, παρακαλώ.
Use a softer “need to”: … αλλά μετά πρέπει να φύγω λίγο. (“…but then I have to go in a bit.”)
Add a reason: … αλλά μετά πρέπει να φύγω γιατί έχω ραντεβού. (“…because I have an appointment.”)