Αν πάμε κατευθείαν στο αεροδρόμιο, θα προλάβουμε την πτήση.

Αν means if. It introduces the condition:

Αν πάμε κατευθείαν στο αεροδρόμιο = If we go straight to the airport

So the whole sentence is a normal if ... then ... structure:

• Αν πάμε ... = if we go ...
• θα προλάβουμε ... = we will catch / make ...

Because Greek normally does not use θα inside an if-clause.

Just like English says If we go, not If we will go, Greek says:

• Αν πάμε = if we go

Then the future meaning appears in the main clause:

• θα προλάβουμε = we will catch / make it

So this pattern is very common:

• Αν + verb
• θα + verb

Yes, it is the same written form: πάμε.

But the meaning depends on context:

• Πάμε! = Let’s go!
• Αν πάμε ... = If we go ...

So the form is the same, but the sentence around it tells you how to understand it.

Both πάω and πηγαίνω can mean go, but they are not always used in exactly the same way.

Here, αν πάμε sounds natural because it refers to one specific trip to the airport. It has the sense of a single complete action.

If you said αν πηγαίνουμε, it would more likely suggest something like:

• if we are going
• if we go regularly
• an ongoing or repeated action

So in this sentence, αν πάμε is the natural choice.

Κατευθείαν means straight, directly, or without stopping / without a detour.

In this sentence:

• Αν πάμε κατευθείαν στο αεροδρόμιο
  means
• If we go straight/directly to the airport

So the idea is that we do not waste time.

Because στο is the contracted form of:

• σε + το = στο

This is completely normal in Greek.

So:

• στο αεροδρόμιο = to the airport / at the airport

You will see this kind of contraction all the time:

• στο = σε το
• στη = σε τη
• στην = σε την

Because the verb of motion tells you that this is a destination.

With πάμε = we go, σε + accusative often means to a place:

• πάμε στο αεροδρόμιο = we’re going to the airport

In another context, the same phrase could mean at the airport, but here the movement makes to the airport the natural meaning.

Not literally in the same way English uses catch.

Προλαβαίνω means something like:

• manage to do something in time
• get there before it is too late
• make it in time

So:

• θα προλάβουμε την πτήση
  means
• we’ll catch the flight
• we’ll make the flight
• we’ll get there in time for the flight

This is a very natural Greek way to express that idea.

Because Greek is using the perfective form here, which is normal for a single completed future event.

The basic verb is προλαβαίνω, but its perfective form is built on προλάβ-:

• προλαβαίνω = I am managing / I manage
• να προλάβω = to manage in time
• θα προλάβουμε = we will manage in time / we will catch

Since catching a flight is seen as one whole event, Greek uses:

• θα προλάβουμε

If you said θα προλαβαίνουμε, that would sound more like an ongoing or repeated situation, which does not fit this sentence well.

Because Greek usually uses the definite article when talking about a specific noun that is understood in the situation.

Here, την πτήση means the flight — a specific flight the speakers have in mind.

So:

• την πτήση = the flight
• μια πτήση = a flight

In this sentence, the meaning is clearly specific, so την is the natural choice.

Because it is the direct object of θα προλάβουμε.

The verb προλαβαίνω / προλάβω takes an object:

• προλαβαίνω την πτήση = I catch / make the flight

So πτήση appears in the accusative singular, and the article also matches that:

• η πτήση = the flight (nominative)
• την πτήση = the flight (accusative)

Yes. Greek word order is more flexible than English word order.

The sentence as given is very natural and neutral:

• Αν πάμε κατευθείαν στο αεροδρόμιο, θα προλάβουμε την πτήση.

But you could also hear:

• Αν πάμε στο αεροδρόμιο κατευθείαν, θα προλάβουμε την πτήση.

That said, not every order sounds equally natural in every context. The original version is a very good standard one.

Because the first part is a subordinate if-clause:

• Αν πάμε κατευθείαν στο αεροδρόμιο = if we go straight to the airport

Then the main clause follows:

• θα προλάβουμε την πτήση = we’ll catch the flight

Greek normally separates that opening conditional clause with a comma, just as English often does.

Yes. Εάν is a more formal or careful version of αν.

So these both work:

• Αν πάμε κατευθείαν στο αεροδρόμιο, θα προλάβουμε την πτήση.
• Εάν πάμε κατευθείαν στο αεροδρόμιο, θα προλάβουμε την πτήση.

In everyday speech, αν is much more common.