Αν τελειώσω αυτή την αναφορά τώρα, ξεμπερδεύω για σήμερα.

Because after αν in a future/open condition, Greek normally uses the perfective non-past form, often called the aorist subjunctive.

So:

• αν τελειώσω = if I finish / if I manage to finish
• αν τελειώνω would not fit this meaning well here

The speaker is talking about completing the report as a single whole action, not about being in the process of working on it.

No. It is not past here.

It uses the same stem you see in the aorist, but in this sentence it is a non-past dependent form after αν. In practical learner terms, you can think of it as:

• τελείωσα = I finished → past
• αν τελειώσω = if I finish → future-oriented condition

So the form may look a little like the past system, but its meaning here is future, not past.

Because in Modern Greek, you normally do not use θα in this kind of if-clause.

So Greek says:

• Αν τελειώσω... = If I finish...

not:

• Αν θα τελειώσω...

That second version is generally not the normal way to express this meaning.

Because αν itself introduces the conditional clause and is followed directly by this verb form.

So you say:

• αν τελειώσω

not:

• αν να τελειώσω

A useful pattern to remember is:

• αν + perfective non-past for open future conditions

This is a very natural feature of conversational Greek. The present can be used for a very immediate, expected result, especially in a sentence like this.

So:

• ξεμπερδεύω για σήμερα here means something like then I’m done for today

It sounds direct and matter-of-fact. A more explicitly future version could be:

• θα ξεμπερδέψω για σήμερα

But the present ξεμπερδεύω is very natural and gives a sense of then that’s it, I’m done.

Here ξεμπερδεύω means something like:

• I’m done
• I get it over with
• I’m finished with my obligations
• I’m free of this for now

It is more idiomatic than just a literal finish. In this sentence, it means that if the speaker finishes the report now, they will have no more work left for today.

Because the report is the direct object of τελειώσω, so it must be in the accusative.

Compare:

• αυτή η αναφορά = nominative, used when it is the subject
  
  • Αυτή η αναφορά είναι δύσκολη.
• αυτή την αναφορά = accusative, used as the object
  
  • Θα τελειώσω αυτή την αναφορά.

So in your sentence, αυτή την αναφορά is correct because the speaker is finishing the report.

Because in Modern Greek, a demonstrative like this is normally used together with the definite article:

• αυτό το βιβλίο = this book
• αυτή την αναφορά = this report

This is standard Greek structure. English says this report with no article, but Greek usually says the equivalent of this the report.

Because the next word, αναφορά, begins with a vowel.

In standard writing, the accusative article keeps the final -ν before vowels:

• την αναφορά
• τον άνθρωπο

Before some consonants, especially in informal writing or speech, you may see the shorter form without -ν in some cases. But before a vowel, την is the normal form.

για σήμερα means for today or as far as today is concerned.

That is slightly different from just σήμερα, which simply means today.

So:

• ξεμπερδεύω για σήμερα = I’m done for today
• ξεμπερδεύω σήμερα would sound more like I finish/get done today, which is a different idea

The phrase για σήμερα sets a limit: the speaker means they will have finished today’s share of the work.

Yes. Greek word order is fairly flexible, and moving words often changes emphasis more than basic meaning.

For example:

• Αν τελειώσω αυτή την αναφορά τώρα... = neutral, natural
• Αν τελειώσω τώρα αυτή την αναφορά... = a bit more emphasis on now

Both are possible. The original sentence sounds very natural.

Yes, but the meaning changes slightly.

• αν = if
• όταν = when

So:

• Αν τελειώσω αυτή την αναφορά τώρα... = If I finish this report now...
• Όταν τελειώσω αυτή την αναφορά... = When I finish this report...

Use αν when the result is still presented as a condition. Use όταν when you mean it more as an expected event.

This is an open or real condition. The speaker presents the situation as a real possibility.

Pattern:

• Αν + perfective non-past
• then a result clause

So the structure is basically:

• If I finish this report now, I’m done for today

A more hypothetical or less realistic sentence would usually use a different tense pattern, for example:

• Αν τελείωνα αυτή την αναφορά τώρα, θα ξεμπέρδευα για σήμερα.

That sounds more like If I were finishing / if I could finish this report now, I’d be done for today.