Χωρίς εκείνον δεν μπορώ να τελειώσω την αναφορά.

It is built into the verb μπορώ.

Greek often drops subject pronouns when they are clear from the verb ending.
So:

• μπορώ = I can
• μπορείς = you can
• μπορεί = he/she/it can

Because of that, Greek does not need εγώ here unless the speaker wants extra emphasis:

• Εγώ δεν μπορώ... = I can’t... / As for me, I can’t...

Χωρίς means without.

It is a very common preposition, and it is used just like English without in many contexts:

• χωρίς εσένα = without you
• χωρίς χρήματα = without money
• χωρίς εκείνον = without him / without that one

Starting the sentence with Χωρίς εκείνον puts a little emphasis on that condition: Without him, ...

Because χωρίς takes the accusative case, and εκείνον is the accusative masculine singular form of εκείνος.

So the forms are:

• εκείνος = he / that one (subject form)
• εκείνον = him / that one (object form)

Here, after χωρίς, Greek needs the object form, so:

• χωρίς εκείνος ❌
• χωρίς εκείνον ✅

Yes, often you could.

Both can mean without him, but there is a slight difference in feel:

• αυτόν = him / this one / that one, often more neutral in everyday speech
• εκείνον = that one / him, often with a stronger sense of that specific person, sometimes a bit more emphatic or contrastive

So:

• Χωρίς αυτόν δεν μπορώ...
• Χωρίς εκείνον δεν μπορώ...

Both are possible, but εκείνον can sound a bit more pointed: without that particular person.

Δεν is the normal negative particle used with finite verbs in statements.

So:

• μπορώ = I can
• δεν μπορώ = I cannot / I can’t

Greek usually places δεν right before the verb:

• δεν ξέρω = I don’t know
• δεν θέλω = I don’t want
• δεν μπορώ = I can’t

Because δεν and μη(ν) are used in different situations.

Use δεν for ordinary negation in statements:

• Δεν μπορώ. = I can’t.
• Δεν έρχεται. = He isn’t coming.

Use μη(ν) mainly with:

• commands
• the subjunctive in certain negative contexts
• set expressions

Examples:

• Μην πας! = Don’t go!
• Θέλω να μην αργήσεις. = I want you not to be late.

In this sentence, the main verb is μπορώ in a normal statement, so δεν is correct.

Because Modern Greek does not normally use an infinitive the way English does.

English says:

• I can finish

Greek says:

• μπορώ να τελειώσω

After verbs like μπορώ, θέλω, πρέπει, ξέρω, Greek usually uses να + verb.

So να is not optional here. It is the normal way to say to finish after can in Greek.

Because Greek is choosing the perfective form here: the idea is to finish completely, not just to be finishing.

• τελειώνω = imperfective base, focuses more on the process or repeated action
• να τελειώσω = perfective subjunctive, focuses on the action as a whole, especially its completion

In this sentence, the speaker means:

• I can’t complete the report

So να τελειώσω is the natural choice.

If you used the imperfective, it would sound more like ongoing or habitual action, which does not fit as well here.

Την is the definite article meaning the, and it agrees with αναφορά.

• αναφορά is feminine singular
• so the accusative singular article is την

That gives:

• την αναφορά = the report

Greek uses articles very regularly, and here the speaker means a specific report, not just any report.

The final -ν of την is kept before a vowel, and αναφορά begins with a vowel sound.

So:

• την αναφορά ✅
• τη αναφορά ❌

More generally, in Modern Greek, this final -ν is kept before vowels and certain consonants, and many speakers/writers keep it quite often in standard writing.

Yes. Greek word order is more flexible than English, although not completely free.

For example, these are both natural:

• Χωρίς εκείνον δεν μπορώ να τελειώσω την αναφορά.
• Δεν μπορώ να τελειώσω την αναφορά χωρίς εκείνον.

The basic meaning stays the same, but the emphasis changes a little:

• Χωρίς εκείνον... puts the condition first: Without him...
• Δεν μπορώ να τελειώσω... χωρίς εκείνον. sounds a bit more neutral

So the original sentence is emphasizing the importance of him from the very beginning.