Prije oluje moramo spustiti jedro.

Because prije requires the genitive case.

• dictionary form: oluja = storm
• after prije: prije oluje = before the storm

So this is a normal case change:

• oluja → nominative singular
• oluje → genitive singular

This is very common in Croatian:

• prije škole = before school
• prije ručka = before lunch
• prije oluje = before the storm

It is in the accusative, but for many neuter singular nouns, the accusative looks the same as the nominative.

So:

• nominative: jedro = a sail
• accusative: jedro = a sail

In this sentence, jedro is the direct object of spustiti (to lower), so it is in the accusative.

This is similar to other neuter nouns:

• vidim more = I see the sea
• otvaramo pismo = we are opening the letter

Moramo is the 1st person plural present tense of morati, which means must / have to.

So:

• moram = I must
• moraš = you must
• mora = he/she/it must
• moramo = we must
• morate = you all must
• moraju = they must

In this sentence, moramo means we must.

After morati, Croatian uses the infinitive of the main verb.

So the structure is:

• moramo + infinitive

Here:

• moramo = we must
• spustiti = to lower

So:

• moramo spustiti = we must lower

You do not say moramo spuštamo, because spuštamo is a finite verb form (we are lowering / we lower), not an infinitive.

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

• spustiti = perfective
• spuštati = imperfective

Here, spustiti is used because the sentence refers to a single completed action: lowering the sail before the storm arrives.

So:

• moramo spustiti jedro = we must lower the sail (one complete action)

If you used spuštati, it would sound more like:

• lowering in progress
• repeated lowering
• focusing on the process rather than completion

A learner-friendly shortcut:

• perfective = do it as a whole / complete it
• imperfective = be doing it / do it repeatedly / focus on the process

Because Croatian usually doesn’t need subject pronouns when the verb ending already shows who the subject is.

Here, moramo already clearly means we must, so mi is unnecessary.

You could say:

• Mi moramo spustiti jedro.

But that usually adds emphasis, for example:

• We must lower the sail.

In neutral sentences, Croatian often leaves pronouns out.

Yes. Croatian word order is fairly flexible, because case endings show grammatical roles.

The original sentence:

• Prije oluje moramo spustiti jedro.

You could also say:

• Moramo spustiti jedro prije oluje.

Both are natural. The difference is mainly focus:

• Prije oluje... puts emphasis on the time frame first
• Moramo spustiti jedro... starts with the obligation

So Croatian word order is not as fixed as English word order, although some versions sound more natural depending on context.

Mostly, yes. In a sentence like this, prije means before in a time sense.

• prije oluje = before the storm

A native English speaker may wonder whether it can also mean physical in front of. Usually, Croatian uses other words for that, such as:

• ispred = in front of
• pred = before / in front of, depending on context

So in this sentence, prije is clearly temporal, not spatial.

Here it is singular: of the storm / before the storm.

That can confuse learners because -e can appear in more than one form in Croatian. But after prije, the noun is expected to be in the genitive singular here:

• oluja = storm
• oluje = of the storm

So prije oluje means before the storm, not before storms.

Because Croatian does not have articles like English a and the.

So jedro can mean:

• a sail
• the sail

And oluja / oluje can mean:

• a storm
• the storm
• depending on context

The exact meaning is understood from the situation, context, and sentence structure. In this sentence, English naturally uses the:

• Before the storm, we must lower the sail.

But Croatian simply says:

• Prije oluje moramo spustiti jedro.

A simple pronunciation guide is:

• Prije ≈ pree-yeh
• oluje ≈ oh-LOO-yeh
• moramo ≈ mo-RA-mo
• spustiti ≈ spoo-STEE-tee
• jedro ≈ YEH-dro

A few helpful notes:

• j in Croatian is pronounced like English y in yes
• je often sounds like ye
• r is usually rolled or tapped
• stress exists, but beginners do not need to master it immediately to be understood

So a rough full pronunciation is:

PREE-yeh oh-LOO-yeh mo-RA-mo spoo-STEE-tee YEH-dro