Δεν μπορώ να ξεχωρίσω αυτή τη λέξη από την άλλη.

Δεν μπορώ να means I cannot / I’m not able to.

• δεν = not
• μπορώ = I can
• να = a particle used before many verb forms, especially after verbs like can, want, must, etc.

So μπορώ να ξεχωρίσω literally means I can to distinguish, but in natural English we translate it as I can distinguish or I can tell apart.

When you make it negative, Greek puts δεν before the verb:

• Μπορώ να ξεχωρίσω. = I can tell apart.
• Δεν μπορώ να ξεχωρίσω. = I can’t tell apart.

After μπορώ να, Greek usually uses the form traditionally called the subjunctive, and in this sentence it is the perfective form: ξεχωρίσω.

That sounds technical, but the practical point is:

• ξεχωρίζω = I distinguish / I am distinguishing / I do distinguish
• να ξεχωρίσω = to distinguish, to manage to tell apart, to identify as separate

With verbs like μπορώ, θέλω, πρέπει, Greek normally uses να + this kind of verb form:

• Μπορώ να πάω = I can go
• Θέλω να δω = I want to see
• Δεν μπορώ να ξεχωρίσω = I can’t tell apart

So ξεχωρίσω is exactly what you expect after μπορώ να here.

Here it means to distinguish, to tell apart, or to recognize the difference between two things.

In other contexts, ξεχωρίζω can also mean:

• to separate
• to stand out
• to single out

But in this sentence, because of από (from) and the two words being compared, the meaning is clearly:

I can’t tell this word apart from the other one.

Because λέξη is a feminine singular noun, and here it is the direct object of the verb.

Breakdown:

• αυτή = this (feminine singular)
• τη = the (feminine singular accusative; short form of την)
• λέξη = word

So αυτή τη λέξη means this word.

Greek often uses both a demonstrative and the article together:

• αυτό το βιβλίο = this book
• αυτή τη λέξη = this word
• εκείνο το σπίτι = that house

This is completely normal in Greek.

τη is a shortened form of την.

In everyday Greek, the final -ν in την is often dropped before certain sounds, especially in speech and very commonly in writing too.

So both of these are possible:

• αυτή την άλλη μέρα
• αυτή τη λέξη

In your sentence, τη λέξη is the normal form.

You may still see την written in some contexts, and some speakers keep the final -ν more often than others. But αυτή τη λέξη is completely standard.

Good question. In Greek, some nouns change form in the accusative, but some don’t change visibly.

λέξη is feminine singular, and in this case the nominative and accusative look the same:

• nominative: η λέξη = the word
• accusative: τη λέξη = the word

So even though it is the object of the verb, the noun itself doesn’t change form here. The article shows the case more clearly than the noun does.

από usually means from, and here it introduces what something is being distinguished from.

So:

• ξεχωρίζω κάτι από κάτι άλλο = distinguish something from something else

In this sentence:

• αυτή τη λέξη = this word
• από την άλλη = from the other one

So the structure is: I can’t distinguish this word from the other one.

Because Greek often leaves out a noun when it is obvious from context.

So την άλλη literally means the other [one], where λέξη is understood.

Full version:

• Δεν μπορώ να ξεχωρίσω αυτή τη λέξη από την άλλη λέξη.

But that sounds repetitive, so Greek naturally says:

• ...από την άλλη.

English does the same thing:

• this word from the other one

άλλη is:

• feminine
• singular
• accusative

It matches the understood noun λέξη, which is feminine.

So:

• η άλλη λέξη = the other word
• την άλλη (λέξη) = the other word / the other one

Greek adjectives must agree with the noun they describe in gender, number, and case.

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

The neutral order here is:

• Δεν μπορώ να ξεχωρίσω αυτή τη λέξη από την άλλη.

But Greek can move things around for emphasis, for example:

• Αυτή τη λέξη δεν μπορώ να την ξεχωρίσω από την άλλη.
• Δεν μπορώ να ξεχωρίσω από την άλλη αυτή τη λέξη.
  This is less neutral and more marked.

The original sentence is the most natural straightforward version.

A useful thing to know is that αυ changes sound depending on the next sound.

In αυτή, the αυ is pronounced like af, because the next sound is voiceless.

So αυτή sounds roughly like aftí.

Then:

• τη = ti
• λέξη = roughly LÉ-xi or LÉ-ksee, depending on how you approximate it in English

So αυτή τη λέξη is approximately: aftí ti LÉxi

Also note:

• the stress is on -τή in αυτή
• the stress is on λέ- in λέξη

In this sentence, the best translation is I can’t tell apart or I can’t distinguish.

Depending on context, English might also say:

• I can’t tell this word from the other one
• I can’t distinguish this word from the other one

Make out is possible in some situations, but it often means read with difficulty or see/hear unclearly, so it is not always the best match.

Here the Greek clearly focuses on distinguishing one thing from another.