Potraje li pretraga krvi dulje, sestra će prvo donijeti karton, a doktorica će doći kasnije.

Potraje li is a compact way to say if it lasts or if it takes longer.

The particle li is used here to form a conditional-type structure with the verb first. This is common in more formal or written Croatian.

So:

• Potraje li pretraga krvi dulje... = If the blood test takes longer...
• A more straightforward version would be Ako pretraga krvi potraje dulje...

In other words, verb + li here functions a lot like if.

Because potrajati is a perfective verb, while trajati is imperfective.

• trajati = to last, to be ongoing
• potrajati = to end up lasting for some time, to last longer than expected

In Croatian, perfective present forms are often used when talking about a future completed or bounded event. Here the sentence is about a possible future situation:

• Ako pretraga krvi potraje dulje... = if the test ends up taking longer

If you used traje, it would sound more like describing an ongoing process rather than a single future possibility.

Because Croatian can express if in more than one way.

Two natural options are:

• Ako pretraga krvi potraje dulje...
• Potraje li pretraga krvi dulje...

These mean essentially the same thing. The verb + li version is a bit more compact and often feels slightly more formal or literary.

Krvi is genitive singular of krv.

Here it depends on pretraga:

• pretraga krvi = examination/test/search of blood

This is a very common Croatian pattern: one noun followed by another noun in the genitive to show what something is connected with.

Examples of the same pattern:

• analiza krvi = blood analysis
• boja zida = the color of the wall
• vrata kuće = the door of the house

So krvi is not the object of the verb here; it belongs to the noun pretraga.

Literally, it is something like an examination/test of blood.

In real medical context, it usually means a blood test or blood work, depending on context.

So while pretraga can sometimes mean search or examination, in this sentence the whole phrase is best understood medically.

Dulje means longer.

Yes, dulje and duže are both used and usually mean the same thing. They are variant comparative forms of dugo (for a long time / long as an adverb).

So:

• dugo = long / for a long time
• dulje / duže = longer

In standard Croatian, dulje is often preferred in careful usage, but you will hear both.

This is the normal Croatian future I:

• ću, ćeš, će, ćemo, ćete, će
  • infinitive

So:

• sestra će donijeti = the nurse will bring
• doktorica će doći = the doctor will come

The infinitives here are:

• donijeti = to bring
• doći = to come

So the pattern is very straightforward: future auxiliary + infinitive.

Because će is a clitic, and Croatian clitics usually go in the second position of the clause.

That means they often come after the first stressed word or phrase.

So:

• sestra će prvo donijeti karton
• doktorica će doći kasnije

Here, the first element in each clause is the subject:

• sestra
• doktorica

So the clitic će comes right after it.

This word order is very normal in Croatian.

Literally, yes, sestra means sister.

But in medical contexts, sestra also means nurse. That is the meaning here.

So in a hospital or clinic:

• sestra = nurse
• doktorica = female doctor

This is a very common source of confusion for English speakers, because the same word has both meanings depending on context.

Because doktorica is the feminine form, meaning a female doctor.

Croatian often marks grammatical gender in profession nouns:

• doktor = male doctor
• doktorica = female doctor

Since the sentence uses doktorica, it tells you the doctor is a woman.

Right — here karton does not mean ordinary cardboard.

In medical Croatian, karton often means a medical chart, patient file, or record.

So in this sentence, sestra će prvo donijeti karton means the nurse will first bring the patient's chart/file.

This is a very context-dependent word.

They are adverbs of sequence/time.

• prvo = first
• kasnije = later

They help organize the order of events:

• first, the nurse brings the chart
• later, the doctor comes

So the sentence is not only saying what will happen, but also in what order.

A often means and, but not always in the simple English sense.

Here it links two clauses while also creating a slight contrast or shift:

• the nurse will do one thing first,
• a the doctor will come later.

So it can feel like:

• and
• while
• whereas
• sometimes even a light but

In this sentence, a helps separate the two roles and the two stages of the situation.

There are two reasons.

1. After the conditional clause

   • Potraje li pretraga krvi dulje, ...

   The opening if-clause is separated from the main clause by a comma.

2. Before a

   • ..., sestra će prvo donijeti karton, a doktorica će doći kasnije.

   The comma marks the boundary between two coordinated clauses.

So the punctuation reflects the sentence structure quite clearly:

• conditional clause
• first main clause
• second main clause introduced by a