Δεν θέλω να πάρω αντιβίωση χωρίς σωστή διάγνωση, γι’ αυτό θα περιμένω μία μέρα ακόμα.

In Modern Greek, verbs like θέλω (I want) are normally followed by να + another verb.

So:

• θέλω να πάρω = I want to take
• not θέλω πάρω

The word να introduces a subordinate verb clause, often corresponding to English to + verb, although it does not work exactly like the English infinitive. Modern Greek does not have an infinitive in the same way English does, so να is the standard way to express this idea.

This is about aspect, which is very important in Greek.

• παίρνω = imperfective stem, focusing on the action as ongoing, repeated, or general
• πάρω = perfective stem, focusing on a single complete action

In this sentence:

• Δεν θέλω να πάρω αντιβίωση...
• the speaker means I don’t want to take antibiotics as a single concrete action, not as a habitual or ongoing process

So πάρω is the natural choice.

A rough contrast:

• Θέλω να παίρνω βιταμίνες κάθε μέρα. = I want to take vitamins every day.
• Θέλω να πάρω αυτό το φάρμακο τώρα. = I want to take this medicine now.

Greek has two common negatives:

• δεν for indicative-type statements
• μη(ν) usually with να, imperatives, and certain non-indicative structures

Here, the negation applies to the main verb θέλω:

• Δεν θέλω... = I do not want...

So δεν is correct because the speaker is negating wanting.

The sentence does not mean I want not to take antibiotics. If you specifically wanted to negate the second verb, you could say:

• Θέλω να μην πάρω αντιβίωση. = I want not to take antibiotics.

But in your sentence, the basic structure is:

• Δεν θέλω = I don’t want
• να πάρω = to take

αντιβίωση means antibiotics or antibiotic treatment.

In everyday Greek, it is often used as a general mass/medical noun, not necessarily referring to a single pill or a single antibiotic by name. So:

• παίρνω αντιβίωση = take antibiotics / be on antibiotics

This is a very common medical expression in Greek.

Greek often omits the article when speaking in a general or indefinite way, especially with substances, treatments, or abstract medical ideas.

So:

• να πάρω αντιβίωση = to take antibiotics / to take antibiotic treatment

This sounds natural because the speaker is not referring to a specific previously identified antibiotic, but to antibiotics in general.

If you added an article, it could sound more specific in some contexts:

• να πάρω την αντιβίωση = to take the antibiotics / the antibiotic treatment

That would usually suggest a specific treatment already known in the conversation.

χωρίς means without, and very often in Greek it is followed by a noun phrase without an article when the meaning is general.

So:

• χωρίς σωστή διάγνωση = without proper diagnosis

This sounds natural and idiomatic.

The alternatives are possible, but they change the nuance:

• χωρίς μια σωστή διάγνωση = without a proper diagnosis
  
  • possible, a little more explicit or countable in feel
• χωρίς τη σωστή διάγνωση = without the correct diagnosis
  
  • more specific, as if there is one particular correct diagnosis being referred to

In your sentence, the general idea is: not without proper diagnosis first, so the article is naturally omitted.

After χωρίς, the noun phrase is in the accusative.

So:

• σωστή = feminine singular accusative
• διάγνωση = feminine singular accusative

They agree in:

• gender: feminine
• number: singular
• case: accusative

Dictionary form:

• σωστός, σωστή, σωστό = correct / proper
• η διάγνωση = diagnosis

Here:

• χωρίς σωστή διάγνωση = without proper diagnosis

A useful thing to notice is that for many feminine nouns like διάγνωση, the nominative and accusative singular look the same.

γι’ αυτό means:

• therefore
• for that reason
• that’s why

It connects the first part of the sentence to the result:

• I don’t want to take antibiotics without proper diagnosis, so/that’s why I will wait...

It is a shortened form of για αυτό.

The apostrophe shows that a vowel has been dropped in pronunciation/spelling:

• για αυτό → γι’ αυτό

Both forms exist, but γι’ αυτό is very common in normal writing.

Be aware that in some contexts γι’ αυτό can also literally mean for this, but here it clearly has the connector meaning therefore / that’s why.

Yes. θα is the particle used to form the future in Modern Greek.

So:

• περιμένω = I wait / I am waiting
• θα περιμένω = I will wait

In this sentence:

• θα περιμένω μία μέρα ακόμα = I will wait one more day

This is the normal way to express the future in Greek.

Many Greek verbs use the same basic non-past form after θα.

So:

• περιμένω can mean I wait / I am waiting
• θα περιμένω means I will wait

The particle θα is what makes it future.

This is completely normal in Greek. The time reference often depends on particles like θα, not on a separate English-style future verb form such as will wait vs wait.

μία is the feminine form of one and also works as the indefinite article a/an in some contexts.

Here it means:

• μία μέρα ακόμα = one more day

The noun μέρα is feminine, so μία must also be feminine.

You may also see μια instead of μία. Both are common:

• μία = slightly fuller spelling, sometimes clearer or more emphatic
• μια = very common everyday spelling

Both are correct in most contexts.

ακόμα can have several meanings depending on context:

• still
• yet
• even
• more / another

In this sentence, it means:

• more / another

So:

• μία μέρα ακόμα = one more day / another day

This is a very common use.

Compare:

• Είναι ακόμα εδώ. = He/She is still here.
• Θέλω ακόμα καφέ. = I want more coffee.
• Μία φορά ακόμα. = One more time.

Yes. μέρα is the common everyday form of ημέρα.

So both exist:

• ημέρα = more formal/full form
• μέρα = very common in everyday speech

In normal conversation, μέρα is extremely natural.

Examples:

• Καλή μέρα = good day
• μία μέρα ακόμα = one more day

So there is nothing unusual here; this is just the usual spoken-style word.

Greek word order is more flexible than English word order, although some versions sound more natural than others.

The original sentence is very natural:

• Δεν θέλω να πάρω αντιβίωση χωρίς σωστή διάγνωση, γι’ αυτό θα περιμένω μία μέρα ακόμα.

You could move some parts around for emphasis, for example:

• Γι’ αυτό θα περιμένω ακόμα μία μέρα.
• Δεν θέλω χωρίς σωστή διάγνωση να πάρω αντιβίωση.

But these may sound slightly more marked, formal, or emphatic depending on context.

So the given word order is best understood as a natural, neutral way to say it.

Yes, both usually mean:

• one more day
• another day

So:

• μία μέρα ακόμα
• ακόμα μία μέρα

are both natural.

There can be a tiny difference in emphasis:

• μία μέρα ακόμα emphasizes the extra amount at the end
• ακόμα μία μέρα puts the idea of one more up front

But in everyday use, they are very close in meaning.