Δεν μπορώ να καταπιώ αυτό το χάπι χωρίς νερό.

Δεν is the basic word for not in Modern Greek. It goes before the finite verb, so here it comes before μπορώ:

Δεν μπορώ = I cannot / I can’t

Greek usually puts the negative directly before the verb it negates. In this sentence, δεν negates the whole idea μπορώ να καταπιώ.

Μπορώ means I can / I am able to.

It is the 1st person singular form of μπορώ:

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

By itself, μπορώ can mean I am able. When it is followed by να + verb, it means I can do something.

So:

• μπορώ = I can
• μπορώ να καταπιώ = I can swallow

After verbs like μπορώ, Greek normally uses να plus another verb.

So the pattern is:

μπορώ να + verb = I can + verb

Examples:

• Μπορώ να έρθω. = I can come.
• Μπορώ να φύγω. = I can leave.
• Μπορώ να καταπιώ αυτό το χάπι. = I can swallow this pill.

English uses the bare infinitive after can (can swallow), but Modern Greek does not have an infinitive in this use. Instead, it uses να + a finite verb form.

This is a very common learner question. Greek often makes a distinction between:

• imperfective: ongoing, repeated, habitual action
• perfective: single, complete action

Here:

• καταπίνω = I swallow / I am swallowing / I swallow in general
• να καταπιώ = to swallow successfully as one complete action

With this pill, Greek naturally uses the perfective form να καταπιώ, because the action is seen as one complete event: swallowing the pill.

Compare:

• Μπορώ να καταπίνω χάπια εύκολα. = I can swallow pills easily.
  (general ability / repeated action)
• Δεν μπορώ να καταπιώ αυτό το χάπι. = I can’t swallow this pill.
  (one specific act)

It is not completely unpredictable, but it does come from a different stem than the present-tense form, so learners often experience it as irregular.

The verb is:

• present/imperfective: καταπίνω
• perfective stem: καταπι-
• subjunctive here: να καταπιώ

This kind of stem change is fairly normal in Greek verbs. So even though it may feel irregular at first, it is part of a common pattern where the present stem and the perfective stem are different.

Because in Greek, demonstratives like this usually appear together with the definite article.

So:

• αυτό το χάπι = this pill
• literally something like this the pill

This is normal Greek structure.

Compare:

• το χάπι = the pill
• αυτό το χάπι = this pill
• εκείνο το χάπι = that pill

English does not use both this and the together, but Greek usually does.

It is in the accusative case, because it is the direct object of καταπιώ.

You are swallowing the pill, so the pill is the object.

Here it is:

• αυτό = neuter singular accusative
• το = neuter singular accusative article
• χάπι = neuter singular noun

Because χάπι is neuter, its nominative and accusative forms look the same. So you do not see a change in the noun itself, but grammatically it is accusative.

Χωρίς νερό means without water in a general, nonspecific sense.

That is the natural choice here, because the speaker means they cannot swallow the pill unless they have some water available.

If you said χωρίς το νερό, it would mean without the water, referring to some specific water already known from context. That is much more specific and usually less natural in this sentence.

So:

• χωρίς νερό = without water
• χωρίς το νερό = without the water

Χωρίς is followed by the accusative.

So in this sentence:

• χωρίς νερό

The noun νερό is neuter singular, and for neuter nouns the nominative and accusative are often identical in form, so it looks unchanged. But grammatically it is accusative after χωρίς.

Other examples:

• χωρίς εσένα = without you
• χωρίς χρόνο = without time
• χωρίς το βιβλίο = without the book

The given order is the most neutral and natural:

Δεν μπορώ να καταπιώ αυτό το χάπι χωρίς νερό.

But Greek word order is more flexible than English, so other versions are possible for emphasis.

For example:

• Χωρίς νερό δεν μπορώ να καταπιώ αυτό το χάπι.
  This emphasizes without water.
• Αυτό το χάπι δεν μπορώ να το καταπιώ χωρίς νερό.
  This emphasizes this pill.

So the original sentence is not the only possible order, but it is a very normal default one.

Yes, if the pill is already clear from context.

Here το is a direct object pronoun meaning it:

• Δεν μπορώ να το καταπιώ χωρίς νερό. = I can’t swallow it without water.

Greek often uses object pronouns when the noun has already been mentioned.

You can even get both the full noun and the pronoun together in some structures, especially for emphasis:

• Αυτό το χάπι δεν μπορώ να το καταπιώ χωρίς νερό.

That is very common in spoken Greek.

Χάπι is the normal everyday word for pill.

In more formal or medical language, you may also see:

• δισκίο = tablet
• sometimes κάψουλα = capsule

But in ordinary speech, χάπι is very common and natural.

So this sentence sounds completely normal in everyday Greek.

A rough pronunciation guide is:

Then bo-RO na ka-ta-PYO af-TO to HA-pi kho-RIS ne-RO

A few helpful pronunciation points:

• μπ in μπορώ sounds like b
• χ in χάπι and χωρίς is a throaty sound, like German Bach or Scottish loch
• Stress matters a lot in Greek:
  • μπορώ
  • καταπιώ
  • αυτό
  • χάπι
  • χωρίς
  • νερό

If you place the stress correctly, you will sound much more natural.

Yes, in many contexts you may hear or see δε instead of δεν:

• δεν μπορώ
• δε μπορώ

Both are used, especially in speech. In careful writing, δεν is very common and is the safest form for learners to use.

So in this sentence, Δεν μπορώ να καταπιώ... is completely standard and natural.