Ako bude potrebno, primit će samo jednu injekciju, ali doktorica kaže da je to malo vjerojatno.

Ako bude potrebno means If it is necessary or more naturally If necessary.

• ako = if
• bude = a future-related form of biti (to be)
• potrebno = necessary / needed

So this clause sets up a condition: If it turns out to be necessary...

After ako (if), Croatian often uses the present form of a perfective verb to refer to the future.

Here, bude is the perfective future-type form used in conditional clauses. So:

• Ako bude potrebno = If it becomes necessary / If it should be necessary

Using ako će biti potrebno is generally not the normal way to say this in standard Croatian.

This is a very common pattern:

• Ako dođe = If he/she comes
• Ako bude vremena = If there is time
• Ako bude potrebno = If it is necessary

So even though English often uses present after if too (if it is necessary), Croatian is using a form that is tied to a future situation.

Primit će means will receive.

It is made of:

• primiti = to receive
• future marker će

In Croatian future tense, when the infinitive ends in -ti, that -ti is dropped before će:

• primiti + će → primit će

That is why it appears as two words:

• primit će not primiti će

Compare:

• raditi → radit će = will work
• doći → doći će = will come
  (this one behaves differently because the infinitive does not end in -ti in the same way)

Because it is the direct object of the verb primit će (will receive), it goes into the accusative case.

Base forms:

• jedna = one (feminine nominative)
• injekcija = injection (nominative)

Accusative forms:

• jednu
• injekciju

So:

• jedna injekcija = one injection as a subject
• primit će jednu injekciju = she will receive one injection

Since injekcija is feminine singular, the number one must also match it:

• nominative: jedna injekcija
• accusative: jednu injekciju

Samo means only / just.

In primit će samo jednu injekciju, it limits jednu injekciju, so the meaning is will receive only one injection.

The placement is natural Croatian word order:

• primit će samo jednu injekciju

You could move words around in Croatian for emphasis, but this is the most neutral and standard order.

Doktorica is the feminine form meaning female doctor.

• doktor = male doctor / doctor in a general masculine form
• doktorica = female doctor

Since the sentence specifically refers to a woman doctor, doktorica is used.

Kaže da je to malo vjerojatno literally means She says that it is a little unlikely, but in natural English: the doctor says that this is unlikely.

Croatian often uses the present tense after verbs like kaže (says) to express a current judgment about a future event.

So:

• doktorica kaže = the doctor says
• da je to malo vjerojatno = that that is somewhat unlikely

It does not need će biti because the speaker is giving a present evaluation of the situation. The doctor is saying right now that the possibility is unlikely.

Yes, literally:

• malo = little / a little
• vjerojatno = probable / likely

But together malo vjerojatno means unlikely or not very likely.

So it is not usually translated word-for-word as a little probable. A more natural English translation is:

• that is unlikely
• that is not very likely

This is a common Croatian expression:

• Vrlo je vjerojatno. = It is very likely.
• Nije vjerojatno. = It is not likely.
• Malo je vjerojatno. = It is unlikely.

To means that or it, and here it refers to the previous idea: the possibility that she will need and receive just one injection.

So the structure is:

• Ako bude potrebno, primit će samo jednu injekciju = If necessary, she will receive only one injection
• ali doktorica kaže da je to malo vjerojatno = but the doctor says that is unlikely

In other words, to points back to the whole previous situation.

The subject is not stated explicitly, because Croatian often leaves it out when it is understood from context.

In primit će, the subject is implied:

• she/he will receive

Since the broader context apparently makes it clear who is being talked about, Croatian does not need to repeat the pronoun.

This is very common in Croatian:

• Doći će sutra. = He/She will come tomorrow.
• Vidjela sam ga. = I saw him.

Pronouns like ona or on are often omitted unless needed for emphasis or clarity.

Croatian clitics, including će, usually go in the so-called second position of their clause.

In primit će samo jednu injekciju, the future auxiliary će appears right after the first stressed word group.

That is why Croatian often sounds different from English in word order. Clitics such as:

• će
• je
• se
• sam, si, smo, ste, su

tend to cluster near the beginning of the clause, usually after the first word or phrase.

So:

• Primit će samo jednu injekciju is the normal order.

Yes, Croatian allows some flexibility in word order, though different orders may sound more marked or emphasize different parts.

For example, these are possible:

• Ako bude potrebno, primit će samo jednu injekciju.
• Ako bude potrebno, samo će jednu injekciju primiti.
• Samo će jednu injekciju primiti ako bude potrebno.

But the original version is the most natural and neutral.

The second part can also shift somewhat:

• ali doktorica kaže da je to malo vjerojatno
• ali doktorica kaže da je malo vjerojatno

In the second version, to is simply omitted because the meaning is still clear.

A few useful points:

• injekciju has several syllables: in-jek-ci-ju
• vjerojatno can be tricky because of the cluster vj
• primit će is spelled as two words, even though in speech it may sound very closely connected
• doktorica clearly marks a female profession noun with -ica

Also notice Croatian spelling is very phonetic compared with English: words are generally pronounced much as they are written.