Ne zaboravi vezati pojas prije nego što krenemo.

It is a 2nd person singular command/reminder addressed to one person.

• zaboravi = imperative form of zaboraviti
• ne = negation

So ne zaboravi means don’t forget when speaking to one person informally.

If you were speaking to:

• more than one person or
• one person formally,

you would say Ne zaboravite...

Yes. That is also very natural.

Both are common:

• Ne zaboravi vezati pojas
• Nemoj zaboraviti vezati pojas

A useful way to feel the difference:

• Ne zaboravi... often sounds like a quick reminder: Don’t forget...
• Nemoj zaboraviti... can sound a little more expanded or explicit

In everyday Croatian, both work well here.

Because after zaboraviti Croatian commonly uses an infinitive to express the action that someone forgets to do.

So the structure is:

• zaboraviti + infinitive

Examples:

• Ne zaboravi nazvati. = Don’t forget to call.
• Ne zaboravi ponijeti ključ. = Don’t forget to bring the key.
• Ne zaboravi vezati pojas. = Don’t forget to fasten the seat belt.

This is similar to English forget to do something.

By itself, pojas means belt. But in this context, it very naturally means seat belt.

That is because the phrase vezati pojas is a very common way to say fasten your seat belt.

If you want to be completely explicit, you can say:

• sigurnosni pojas = safety belt / seat belt

So:

• vezati pojas = fasten the seat belt
• vezati sigurnosni pojas = fasten the safety belt / seat belt

Because pojas is the direct object of vezati, so it is in the accusative case.

The important detail is that pojas is a masculine inanimate noun, and for many masculine inanimate nouns, the nominative and accusative singular look the same.

So:

• nominative: pojas
• accusative: pojas

That is why the word does not visibly change here.

It means before and introduces a subordinate clause.

Breakdown:

• prije = before
• nego što = than / that, as part of this fixed expression

Together, prije nego što functions as before in English when followed by a clause:

• prije nego što krenemo = before we leave / before we set off

This is a very common Croatian structure.

Yes, very often.

You can hear both:

• prije nego što krenemo
• prije nego krenemo

Both are common and natural. The version with što is simply the fuller form.

So for a learner, it is good to recognize both as meaning the same thing here.

Because after time expressions like prije nego što, Croatian often uses the present tense even when the meaning is future.

So although krenemo is formally present tense, in this sentence it means something like:

• before we leave
• before we set off

This is very normal Croatian usage.

A similar pattern appears with words like:

• kad = when
• dok = while / until
• čim = as soon as

So Croatian does not always use a future form where English might expect future meaning.

Because krenuti and ići are related but not identical.

• krenuti = to set off, to start going, to leave
• ići = to go

In this sentence, the focus is on the moment of departure, so krenemo is very natural.

Compare:

• prije nego što krenemo = before we set off / before we leave
• prije nego što idemo would usually sound less natural here

So krenemo fits the travel/departure situation better.

Because Croatian usually drops subject pronouns when they are already clear from the verb ending.

Here:

• zaboravi tells you this is a command to you singular
• krenemo tells you the subject is we

So Croatian does not need to say:

• Ti ne zaboravi...
• ...prije nego što mi krenemo

Those pronouns would only be added for emphasis, contrast, or special context.

Yes.

krenemo comes from krenuti, which is a perfective verb. In Croatian, a perfective present often has future meaning, especially in subordinate clauses like this one.

So here:

• krenemo is grammatically present
• but semantically it refers to a future action: when we set off / when we leave

This is a very important Croatian pattern, and English speakers often notice it early because it does not match English tense usage exactly.