Ako je to samo simptom prehlade, ona će brzo ozdraviti.

Prehlade is the genitive singular of prehlada.

Here it comes after the noun simptom, because Croatian often uses the genitive to express of relationships:

• simptom prehlade = symptom of a cold

So this is a very common pattern:

• uzrok problema = cause of the problem
• boja auta = color of the car
• simptom prehlade = symptom of a cold

Because je is a clitic. In Croatian, clitics usually stand very early in the clause, typically in second position.

So Croatian prefers:

• Ako je to samo simptom prehlade...

not:

• Ako to je...

This is one of the most important word-order habits in Croatian. Forms like je, sam, si, smo, ste, su, će often behave this way.

After ako meaning if, Croatian normally uses the present tense for a real future possibility, just like English often does:

• Ako je to samo simptom prehlade, ona će brzo ozdraviti.
• If it is only a symptom of a cold, she will recover quickly.

So the structure is:

• ako + present
• main clause in future

Using a future form in the ako clause would usually sound unnatural here.

To here means something like that or it, referring to some sign, symptom, or situation already being discussed.

It is the neuter singular form often used for:

• something unspecified
• an idea
• a situation
• something pointed out indirectly

So to does not have to refer to a neuter noun right next to it. It can simply mean that / it in a general sense.

Ona refers to she: the female person who will recover.

It does not refer to prehlada, even though prehlada is also feminine. In this sentence, ona is the subject of će ozdraviti.

It is often optional in Croatian, because the verb form already shows the person and number. So you could also say:

• Ako je to samo simptom prehlade, brzo će ozdraviti.

Adding ona can give:

• extra clarity
• contrast
• emphasis

This is the future tense.

Croatian forms the future here with:

• će = auxiliary
• ozdraviti = infinitive

So:

• ona će ozdraviti = she will recover / she will get well

This is a standard future pattern in Croatian.

You may also see a different word order in other sentences, such as:

• Ozdravit će brzo.

That is also future tense.

Ozdraviti means to recover, to get well, to become healthy again.

It is a perfective verb, which means it presents the action as reaching a result or completion. That fits well here, because the idea is that she will recover fully, not just be in the process of recovering.

So će ozdraviti suggests:

• she will get better
• she will recover

rather than focusing on the process itself.

Because brzo is an adverb, and it modifies the verb ozdraviti:

• brzo ozdraviti = to recover quickly

The forms brz, brza, brzo can be adjectives, but when you want to say quickly, Croatian uses the adverb form brzo.

Compare:

• brza žena = a fast woman
• brzo trči = she runs quickly

Samo means only or just.

In this sentence it limits simptom prehlade:

• to samo simptom prehlade = that is only a symptom of a cold

The sense is:

• not something more serious
• merely a symptom of a cold

So samo adds the idea of reassurance or minimization.

Either can be possible, depending on context.

Croatian has no articles, so nouns do not automatically show the difference between:

• a cold
• the cold

That distinction is understood from the situation.

So simptom prehlade can mean:

• symptom of a cold
• symptom of the cold

In many learning contexts, a cold is the most natural translation.

Yes, it can:

• Ako je to samo simptom prehlade, brzo će ozdraviti.

This still means the same thing.

The version with ona is a little more explicit and can sound:

• clearer
• more contrastive
• slightly more emphatic

Croatian often leaves out subject pronouns unless there is a reason to include them.