Αν σε βολεύει το απόγευμα, μπορώ να σε περιμένω στην είσοδο της τράπεζας.

Here Αν means if: Αν σε βολεύει το απόγευμα... = If the afternoon works for you...

It is the normal word for introducing a condition in Modern Greek.

A couple of useful notes:

• αν = if
• it is often followed by a verb in the present tense when English might also use the present:
  • Αν έχεις χρόνο, έλα. = If you have time, come.

So in this sentence, Αν introduces the condition under which the speaker can wait.

σε βολεύει means something like:

• it suits you
• it is convenient for you
• it works for you

So Αν σε βολεύει το απόγευμα is literally close to If the afternoon suits you.

It is not exactly the same as:

• you want
• you can

The verb βολεύω / βολεύομαι is about convenience or what is practical.

Examples:

• Σε βολεύει αύριο; = Does tomorrow suit you?
• Δεν με βολεύει αυτή η ώρα. = That time doesn’t work for me.

The σε means you as an object pronoun.

In σε βολεύει, the literal structure is something like:

• it suits you
• it is convenient for you

So:

• με βολεύει = it suits me
• σε βολεύει = it suits you
• τον/την βολεύει = it suits him/her

Greek often uses weak object pronouns like this where English uses a fuller phrase such as for you or you.

Yes, in this sentence το απόγευμα is effectively the thing that suits the person.

So the structure is:

• το απόγευμα = the afternoon
• σε βολεύει = suits you

Together:

• το απόγευμα σε βολεύει = the afternoon suits you

Greek word order is flexible, so Σε βολεύει το απόγευμα; is very natural, even though the subject comes later.

Also, το απόγευμα can sometimes mean in the afternoon in other contexts, but here it is best understood as the afternoon as the time option being discussed.

να introduces a subordinate verb, often corresponding to English to in sentences like this.

So:

• μπορώ = I can
• να περιμένω = to wait

Together:

• μπορώ να περιμένω = I can wait

This is a very common Greek pattern:

• θέλω να πάω = I want to go
• μπορώ να έρθω = I can come
• πρέπει να φύγουμε = we must leave

So να is an essential part of forming this kind of clause in Modern Greek.

περιμένω is present tense in form, but after μπορώ να it expresses the action the speaker is able/willing to do.

So:

• μπορώ να σε περιμένω = I can wait for you

Even though the waiting would happen later, Greek does not need a future form here, because the idea is governed by μπορώ (I can).

If you wanted to make the waiting explicitly future without μπορώ, you could say:

• Θα σε περιμένω = I will wait for you

But in your sentence, the main idea is I am able / I can do that, not simply I will do that.

This second σε is again the object pronoun you, but now it belongs to περιμένω.

So:

• περιμένω = I wait / I am waiting
• σε περιμένω = I wait for you / I’m waiting for you

Greek uses the direct object pronoun here, where English uses for you.

So the two instances of σε do different jobs:

• σε βολεύει = it suits you
• σε περιμένω = I wait for you

They both mean you, but each belongs to a different verb.

στην is a contraction of:

• σε
  • την → στην

This is very common in Greek.

Examples:

• σε + το → στο
• σε + τη(ν) → στη(ν)
• σε + τους → στους

So:

• στην είσοδο = at/to the entrance

As for είσοδο, it is in the accusative singular, because σε takes the accusative.

Dictionary form:

• η είσοδος = the entrance (nominative)

After σε:

• στην είσοδο = at/to the entrance (accusative)

Because της τράπεζας means of the bank.

The phrase is:

• η είσοδος = the entrance
• της τράπεζας = of the bank

So:

• η είσοδος της τράπεζας = the entrance of the bank / the bank entrance

This is the genitive case, which is often used to show possession or close relationship.

Dictionary form:

• η τράπεζα = the bank

Genitive singular:

• της τράπεζας = of the bank

It can mean either at or to, depending on context, because σε covers both ideas in many situations.

Here, with περιμένω, the natural meaning is:

• at the entrance of the bank

So the speaker is saying where they can wait.

Compare:

• Είμαι στην είσοδο. = I’m at the entrance.
• Πάω στην είσοδο. = I’m going to the entrance.

The verb usually makes the meaning clear.

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

Your sentence is completely natural:

• Αν σε βολεύει το απόγευμα, μπορώ να σε περιμένω στην είσοδο της τράπεζας.

But other orders are also possible, depending on emphasis. For example:

• Αν το απόγευμα σε βολεύει, μπορώ να σε περιμένω στην είσοδο της τράπεζας.
• Μπορώ να σε περιμένω στην είσοδο της τράπεζας, αν σε βολεύει το απόγευμα.

The meaning stays basically the same, but the focus may shift slightly.

It is generally neutral to polite informal.

A few clues:

• σε shows the speaker is addressing one person informally (you singular informal).
• The phrasing is polite and natural for everyday conversation.

If you wanted to address someone formally, you would usually use the plural/formal pronoun forms instead:

• Αν σας βολεύει το απόγευμα, μπορώ να σας περιμένω στην είσοδο της τράπεζας.

So the original sentence is appropriate for a friend, acquaintance, colleague you address informally, and many everyday situations where εσύ is normal.

They are close, but not identical.

• μπορώ να σε περιμένω = I can wait for you
  • emphasizes ability, possibility, or willingness
• θα σε περιμένω = I will wait for you
  • emphasizes a future action/decision

In your sentence, μπορώ να σε περιμένω sounds like:

• If the afternoon works for you, I can wait for you at the bank entrance.

This suggests the speaker is offering a possible arrangement.

If you said:

• Αν σε βολεύει το απόγευμα, θα σε περιμένω στην είσοδο της τράπεζας.

that would sound more like:

• If the afternoon works for you, I’ll wait for you at the bank entrance.

That version is a bit more definite.