Večeras ću odneti poklon sestri.

Večeras is an adverb meaning tonight / this evening. In Serbian, you often use it by itself, without a preposition.

So:

• Večeras = tonight / this evening
• not u večeras or anything similar

It works like a time adverb and can be placed at the beginning for emphasis on time:

• Večeras ću odneti poklon sestri. = Tonight I will take the gift to my sister.

Ću is the 1st person singular future auxiliary, meaning I will.

In Serbian, the future tense is often made with:

• a form of hteti used as an auxiliary
• plus the infinitive of the main verb

So here:

• ću = I will
• odneti = to take / to carry away / to bring away

Together:

• ću odneti = I will take

It is separate because that is a normal way to form the future in Serbian.

Serbian clitics, including ću, usually go in the second position of the sentence or clause.

In this sentence, the first element is Večeras, so ću comes right after it:

• Večeras ću odneti poklon sestri.

This is a very common Serbian pattern.

If you change the word order, ću still tends to stay in second position:

• Poklon ću odneti sestri večeras.

So the placement is grammatical, not random.

This is mainly about aspect.

• nositi is imperfective: carrying, taking habitually, repeatedly, or in an ongoing way
• odneti is perfective: to take something away as a completed action

Since the sentence refers to one completed future action—taking the gift this evening—odneti is the natural choice.

So:

• Večeras ću odneti poklon sestri. = one completed act tonight
• Večeras ću nositi poklon sestri. would sound unusual in most contexts, because it focuses more on the process of carrying

The prefix od- often adds the idea of away, off, or movement from one place to another away from the speaker/reference point.

So odneti suggests take away / carry away / bring over depending on context.

A useful contrast is:

• doneti = bring here / bring toward
• odneti = take there / take away

So if the speaker is taking the gift to the sister, not bringing it to where the speaker currently is, odneti makes sense.

Poklon is the direct object of the verb, so it is in the accusative case.

However, poklon is a masculine inanimate noun, and for many masculine inanimate nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• nominative: poklon
• accusative: poklon

That is why the form does not change.

Sestri is the dative singular of sestra.

The dative is used for the recipient—the person something is given, sent, shown, taken, or brought to.

Here, the sister is the person receiving the gift, so Serbian uses the dative:

• sestra = sister
• sestri = to the sister / to my sister

So:

• poklon sestri = a gift to my sister

Because Serbian usually expresses that meaning through case endings, not through a separate word.

In English:

• to my sister

In Serbian:

• sestri

The dative ending already carries the meaning of to.

So Serbian often packs into one word what English expresses with a preposition plus a noun.

Serbian often leaves out possessives like my when the meaning is obvious from context.

So sestri can mean:

• to the sister
• to his/her sister
• to my sister

depending on context

If you want to make it explicit, you can say:

• Večeras ću odneti poklon svojoj sestri. = Tonight I will take the gift to my sister.

Here, svojoj is the dative singular form of the reflexive possessive adjective, meaning my own / his own / her own depending on the subject.

Yes. That is also correct.

Serbian has two common ways to express this kind of future:

• ću odneti
• odneću

So both are possible:

• Večeras ću odneti poklon sestri.
• Večeras odneću poklon sestri.

The meaning is basically the same. The version with ću + infinitive is very common, and the fused form odneću is also standard.

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

Possible variations include:

• Večeras ću odneti poklon sestri.
• Poklon ću večeras odneti sestri.
• Sestri ću večeras odneti poklon.

These can all be grammatical, but the emphasis changes.

For example:

• Večeras... emphasizes when
• Poklon... emphasizes what
• Sestri... emphasizes to whom

The main restriction is that clitics like ću normally stay near the second position.

No. Serbian does not have articles like a, an, or the.

So:

• poklon can mean a gift or the gift
• sestri can mean to a sister or to the sister

Context tells you which meaning is intended.

That is completely normal in Serbian.

There are two main clues:

1. Večeras points to a specific time: tonight
2. odneti is perfective, which fits a single completed action

Together, they strongly suggest:

• I will take the gift to my sister tonight as one specific event

If Serbian wanted to express habit or repetition, it would usually use a different aspect and a different time expression.