Jutros je bilo samo pet stupnjeva, pa sam se gotovo smrznula dok sam čekala autobus.

Jutros means this morning — specifically, the morning of the current day.

So:

• Jutros je bilo samo pet stupnjeva. = This morning it was only five degrees.

By contrast, ujutro usually means in the morning in a more general sense:

• Ujutro pijem kavu. = I drink coffee in the morning.
• Sutra ujutro = tomorrow morning

So jutros is specific; ujutro is more general or part of a larger time expression.

Because je is a clitic, and Croatian clitics normally go in the second position in the clause.

Here, Jutros is the first element, so the clitic je comes right after it:

• Jutros je bilo...

This is the normal word order.

You may also hear:

• Bilo je jutros...

but that changes the emphasis a bit. The sentence in your example is the most neutral and natural way to say it.

Here bilo is part of the past tense of biti (to be):

• je bilo = was

Croatian often uses an impersonal construction for weather, time, and temperature. English says it was five degrees, but Croatian usually does not need a dummy subject like it.

So:

• Jutros je bilo samo pet stupnjeva. literally = This morning was only five degrees but naturally = This morning it was only five degrees

The form bilo is neuter singular, which is the normal form in these impersonal expressions.

Because numbers in Croatian affect the form of the noun.

With 5 and above, the noun normally goes in the genitive plural:

• pet stupnjeva = five degrees
• šest minuta = six minutes
• deset godina = ten years

Compare:

• jedan stupanj
• dva / tri / četiri stupnja
• pet stupnjeva

So pet stupnjeva is exactly what you expect after pet.

Usually, yes. In everyday Croatian, if someone says:

• Bilo je pet stupnjeva

the default assumption is five degrees Celsius, unless another scale is mentioned.

If you want to be explicit, you can say:

• pet stupnjeva Celzija

But in normal conversation, Celzija is often omitted.

Here pa means something like so, and so, or therefore.

It links the first clause to the result in the second clause:

• Jutros je bilo samo pet stupnjeva, pa sam se gotovo smrznula...
• It was only five degrees this morning, so I almost froze...

It is very common in spoken and written Croatian for connecting events in a natural, conversational way.

Because Croatian usually drops subject pronouns when they are not needed.

The verb form already shows the person:

• sam čekala = I waited / I was waiting
• sam se gotovo smrznula = I almost froze

So ja is unnecessary unless you want extra emphasis or contrast:

• Ja sam čekala autobus, a ona tramvaj. = I was waiting for the bus, and she was waiting for the tram.

In your sentence, leaving out ja is completely normal.

Because of the past participle endings:

• smrznula
• čekala

The ending -la shows a feminine singular speaker.

So this sentence was said by a woman or girl.

If the speaker were male, you would expect:

• Jutros je bilo samo pet stupnjeva, pa sam se gotovo smrznuo dok sam čekao autobus.

So Croatian past tense often tells you the speaker’s gender.

Se is the reflexive particle.

The verb is smrznuti se, which means to freeze / get frozen / freeze up in this kind of context.

So:

• smrznuti = to freeze something
• smrznuti se = to freeze oneself / to get very cold / to freeze

In English, we usually would not say I froze myself, but Croatian often uses reflexive verbs where English does not.

So:

• sam se gotovo smrznula = I almost froze

Yes. Here gotovo means almost.

So:

• gotovo smrznula = almost froze

It modifies the whole action, not the temperature.

Compare:

• gotovo sam pala = I almost fell
• gotovo smo zakasnili = we were almost late

In your sentence, it means she got extremely cold while waiting.

Croatian does not have a separate tense exactly like the English past continuous (was waiting).

Instead, Croatian often uses:

• the normal past tense
• plus an imperfective verb
• plus context

Here:

• čekati is an imperfective verb
• dok means while

So:

• dok sam čekala autobus naturally means
• while I was waiting for the bus

In other words, the sense of an ongoing past action comes from čekati being imperfective and from the conjunction dok.

Because dok usually means while, showing that one action was happening during another.

Here the idea is:

• she was waiting for the bus
• during that time, she almost froze

So dok is the right choice:

• dok sam čekala autobus = while I was waiting for the bus

If you used kad, it would more naturally mean when, which can sound more like a single point in time rather than an ongoing background action.

Because the verb čekati takes a direct object in the accusative case.

So Croatian says:

• čekati autobus = to wait for a bus / the bus
• čekati prijatelja = to wait for a friend

English needs for, but Croatian does not.

That is a very common difference between the two languages.

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

So:

• nominative: autobus
• accusative: autobus

That is why there is no visible ending change here.

Compare that with an animate masculine noun:

• nominative: prijatelj
• accusative: prijatelja

So autobus really is in the accusative — it just happens to look unchanged.

Because there are two separate past-tense verbs:

1. sam se gotovo smrznula
2. sam čekala

Each past-tense verb needs its own auxiliary:

• sam = I have / I did as the auxiliary for first person singular

So the sentence contains:

• one past action in the main clause: I almost froze
• one past action in the subordinate clause: I was waiting

That is why sam appears twice.