Sutra putujemo prema planini, pa nosim svoj kaput.

In Serbian, sutra by itself means tomorrow. You do not need an article or a preposition.

So:

• Sutra putujemo... = Tomorrow we’re traveling...

Serbian also has danas = today and juče = yesterday.

Serbian very often uses the present tense for a planned or scheduled future action, especially when there is a time word like sutra.

So:

• Sutra putujemo literally looks like Tomorrow we travel / are traveling
• but naturally means Tomorrow we’re traveling

This is very common in Serbian and works a lot like English sentences such as Tomorrow we leave.

Putujemo is the 1st person plural present tense of putovati = to travel.

It means:

• we travel
• we are traveling
• in context, we are traveling tomorrow

The ending -mo often tells you the subject is we.

Because the preposition prema requires the dative case.

The noun planina means mountain.
Its dative singular form is planini.

So:

• planina = mountain
• prema planini = toward the mountain / toward the mountain area

This is a very useful pattern:

• prema gradu = toward the city
• prema školi = toward the school
• prema moru = toward the sea

Prema usually means toward, in the direction of, or sometimes according to, depending on context.

In this sentence, it means toward:

• putujemo prema planini = we’re traveling toward the mountain

This does not strongly emphasize entering or reaching the mountain itself. It focuses more on the direction.

If you wanted a different nuance, Serbian might use something else, for example:

• u planinu = into the mountain area / to the mountains

So prema planini is about direction.

Here pa links the two parts of the sentence and means something like:

• so
• and so
• therefore
• sometimes just and then, depending on context

In this sentence:

• Sutra putujemo prema planini, pa nosim svoj kaput.

it gives the idea:

• Tomorrow we’re traveling toward the mountain, so I’m taking/wearing my coat.

It sounds natural and conversational.

Because pa is connecting two clauses:

• Sutra putujemo prema planini
• nosim svoj kaput

In Serbian, it is normal to put a comma before pa when it joins clauses like this.

So the punctuation here is standard.

Nosim can mean both:

• I wear
• I carry / I bring / I’m taking

The exact meaning depends on context.

With kaput (coat), the sentence could suggest:

• I’m wearing my coat
• I’m taking my coat
• I’m bringing my coat

Because the sentence talks about tomorrow’s trip, many learners will understand it as I’m taking my coat or I’m bringing my coat along. But in the right context, I’m wearing my coat is also possible.

This is a very important Serbian feature.

Svoj is a reflexive possessive adjective, used when the possessor is the same as the subject.

Here the subject of nosim is I, and the coat belongs to that same person, so Serbian normally prefers:

• nosim svoj kaput = I’m carrying/wearing my own coat

If you said moj kaput, it would still be understandable, but svoj is more natural and more idiomatic when the subject owns the thing.

Compare:

• Nosim svoj kaput. = I’m wearing/carrying my own coat.
• On nosi svoj kaput. = He is wearing/carrying his own coat.
• On nosi moj kaput. = He is wearing/carrying my coat.

So svoj helps avoid ambiguity.

Kaput is the direct object of nosim, so it is in the accusative case.

However, kaput is a masculine inanimate noun, and for many masculine inanimate nouns, the nominative and accusative singular look the same.

So:

• nominative: kaput
• accusative: kaput

That is why the form does not visibly change.

You can still tell it is the object from the sentence structure and the verb.

Because Serbian has no articles.

English says:

• the mountain
• a coat
• my coat

Serbian simply uses the noun without a/the, and context tells you the meaning:

• planini = the mountain / a mountain, depending on context
• kaput = coat / the coat
• svoj kaput = my own coat

This is completely normal in Serbian.

Yes. Serbian word order is more flexible than English word order.

The sentence as given is natural:

• Sutra putujemo prema planini, pa nosim svoj kaput.

But other orders are possible for emphasis, for example:

• Sutra prema planini putujemo, pa nosim svoj kaput.
• Svoj kaput nosim, pa sutra putujemo prema planini.
  (less neutral, more marked/emphatic)

The original sentence is the most straightforward and neutral for a learner.

Because the first verb and the second verb have different endings:

• putujemo = we travel
• nosim = I carry/wear

So the sentence means:

• Tomorrow we’re traveling toward the mountain, so I’m taking/wearing my coat.

This is perfectly normal. The speaker is talking first about what we are doing together, and then about what I am doing personally.

Yes, both are imperfective:

• putovati = to travel
• nositi = to carry / wear

That fits the sentence well because it describes:

• a planned trip in progress or as an event
• the speaker’s ongoing or intended action of taking/wearing the coat

In this sentence, aspect is not the main difficulty, but it is useful to know that Serbian often uses imperfective present forms in future contexts when the future is already clear from a word like sutra.