Noćas sam se probudila zbog grmljavine.

Noćas means tonight / during the night, and in many contexts it is naturally understood as last night or earlier this night, depending on when the speaker is talking.

In this sentence, because the speaker says I woke up, English will usually translate it as last night or during the night.

A few useful contrasts:

• noćas = tonight / during the night
• sinoć = last night, specifically last evening/night
• večeras = this evening / tonight

So Noćas sam se probudila... is about something that happened in the night.

In Croatian, the subject pronoun is often omitted because the verb form already shows who is doing the action.

Here, sam is the auxiliary for I in the past tense, so ja is not necessary.

• (Ja) sam se probudila = I woke up

You can include ja for emphasis:

• Ja sam se probudila zbog grmljavine. = I woke up because of the thunder.

But in normal neutral speech, leaving out ja is more natural.

This is the Croatian past tense (often called the perfect).

It is formed with:

• the auxiliary sam = I am / have in this tense structure
• the past participle probudila

So:

• sam probudila = I woke up / I have woken up

With the reflexive particle included:

• sam se probudila = I woke up

The participle changes for gender:

• probudila = feminine speaker
• probudio = masculine speaker

So the whole form tells you:

• past tense
• first person singular
• feminine speaker

Because the speaker is female.

In Croatian past tense, the participle agrees with the gender of the subject:

• Ja sam se probudila = a woman is speaking
• Ja sam se probudio = a man is speaking

This is very common in Croatian and other Slavic languages. English does not show this kind of agreement in the verb, so it often feels unusual to learners.

Se is a reflexive particle. In this sentence, it is part of the verb probuditi se, which means to wake up.

Compare:

• probuditi nekoga = to wake someone up
• probuditi se = to wake up

So:

• Probudila sam dijete. = I woke the child up.
• Probudila sam se. = I woke up.

In your sentence, se is necessary because the meaning is to wake up oneself / to wake up.

This is due to Croatian word-order rules for short unstressed words, often called clitics.

Both sam and se are clitics, and they usually appear near the beginning of the sentence in a fixed pattern.

So this word order is natural:

• Noćas sam se probudila zbog grmljavine.

You will very often see clitics grouped together like this after the first stressed element of the sentence.

For a learner, the key point is: in neutral Croatian, sam se probudila is the normal sequence here.

The basic verb is probuditi se.

That is the infinitive form meaning to wake up.

From it you get forms like:

• probuditi se = to wake up
• probudim se = I wake up / I will wake up, depending on context
• probudila sam se = I woke up

Without se, the verb can be transitive:

• probuditi = to wake someone/something up

So when learning vocabulary, it is best to learn this one as probuditi se.

Because zbog requires the genitive case.

The noun grmljavina is in the nominative in its basic form:

• grmljavina = thunder

After zbog, it changes to genitive singular:

• zbog grmljavine = because of the thunder

This is a very important pattern:

• zbog kiše = because of the rain
• zbog vjetra = because of the wind
• zbog buke = because of the noise

So zbog + genitive is the rule to remember.

Grmljavina means thunder or thundering.

In this sentence, zbog grmljavine means because of the thunder.

Related weather words:

• grmjeti = to thunder
• munja = lightning
• oluja = storm
• kiša = rain

So the sentence means the speaker woke up because the thunder was loud enough to wake her.

Yes. Croatian word order is more flexible than English word order, although some versions sound more neutral than others.

Neutral and natural:

• Noćas sam se probudila zbog grmljavine.

Also possible:

• Zbog grmljavine sam se probudila noćas.
• Sam se probudila zbog grmljavine noćas. — this is not normal at the beginning; clitics usually should not start the sentence
• Probudila sam se noćas zbog grmljavine.

Different orders can shift emphasis. For example:

• Noćas... emphasizes when
• Zbog grmljavine... emphasizes why

But the original sentence is a very natural standard version.

It depends on context, because English and Croatian divide time expressions a little differently.

Croatian noćas refers to this night / during the night. If the speaker is talking the next morning about something that happened overnight, English will usually say:

• I woke up last night because of the thunder.

If the speaker is talking during the same night, English might say:

• I woke up tonight because of the thunder.

So the Croatian sentence itself is fine; the exact English translation depends on the situation.

A rough pronunciation guide:

• Noćas ≈ NO-chas
• sam ≈ sahm
• se ≈ seh
• probudila ≈ pro-boo-DEE-lah
• zbog ≈ zbog (with the z and b close together)
• grmljavine ≈ germ-lya-VEE-neh or more carefully grm-lya-VEE-neh

A few sounds to notice:

• ć in Noćas is softer than English ch
• lj in grmljavine is like the lli in million for many English speakers
• Croatian spelling is quite regular, so words are usually pronounced close to how they are written

Yes, radi + genitive can also mean because of, but zbog is usually the more common and neutral everyday choice here.

So both are possible:

• Noćas sam se probudila zbog grmljavine.
• Noćas sam se probudila radi grmljavine.

However, zbog is the form most learners should probably use first, because it is very common and straightforward.