Ona želi da mi da haljinu, a ja želim da njoj dam jaknu.

In Serbian, after verbs like želeti (to want), it is very common to use da + present tense instead of an infinitive.

So:

• želi da da = she wants to give
• želim da dam = I want to give

This is one of the most important patterns in Serbian. English uses to give, but Serbian usually uses da plus a present-tense verb.

Because these are two different words that just happen to look the same.

In želi da mi da:

• the first da is a conjunction meaning something like to / that
• the second da is the verb gives

So the structure is:

• želi = wants
• da = to
• mi = to me
• da = give / gives

The second da is the 3rd person singular present form of dati (to give).

That is why the sentence can look strange at first, but it is completely normal Serbian.

Both mean an indirect object in the dative case:

• mi = to me
• njoj = to her

But they are different types of pronouns:

• mi is a short, unstressed clitic form
• njoj is a full, stressed form

So:

• da mi da haljinu = to give me the dress
• da njoj dam jaknu = to give her the jacket

The speaker uses njoj instead of the short form joj because it sounds more contrastive or emphatic here: she wants to give me a dress, and I want to give her a jacket.

Yes. You could say:

Ona želi da mi da haljinu, a ja želim da joj dam jaknu.

That would also be correct.

The difference is mainly emphasis:

• joj = neutral, unstressed to her
• njoj = stressed, more emphatic to her

In this sentence, njoj nicely highlights the contrast between mi and njoj:

• she gives me
• I give her

Because they are direct objects, so they go into the accusative singular.

Dictionary forms:

• haljina = dress
• jakna = jacket

Accusative singular:

• haljinu
• jaknu

This is a very common pattern for feminine nouns ending in -a:

• nominative -a
• accusative -u

For example:

• Imam knjigu. = I have a book.
• Vidim sestru. = I see my sister.

So here:

• da haljinu is not correct
• da haljinu? No, because after give the thing being given is the direct object, so you need haljinu
• da jaknu similarly needs jaknu

Because the verb must agree with the subject.

The verb is dati (to give), and its present forms are irregular:

• ja dam = I give
• ti daš = you give
• on/ona/ono da = he/she/it gives
• mi damo
• vi date
• oni daju

So:

• ona želi da mi da haljinu
  = she wants to give me a dress
• ja želim da njoj dam jaknu
  = I want to give her a jacket

The first clause has subject ona, so the form is da.
The second clause has subject ja, so the form is dam.

Because mi is a clitic, and Serbian clitics usually appear very early in the clause, often in the second position.

So Serbian prefers:

• da mi da haljinu

rather than:

• da da mi haljinu

The short pronoun naturally comes before the main verb.

This is a general Serbian pattern with short pronouns like:

• mi = to me
• ti = to you
• mu = to him
• joj = to her
• ga = him/it
• je = her/it

So word order here is not random; it follows normal clitic placement rules.

Here a connects the two clauses and shows contrast or comparison.

In this sentence:

Ona želi da mi da haljinu, a ja želim da njoj dam jaknu.

it means something like:

• and
• while
• whereas
• sometimes even but, depending on context

A natural English sense here is:

• She wants to give me a dress, and I want to give her a jacket.
• or She wants to give me a dress, while I want to give her a jacket.

So a often links two ideas that are parallel or contrasted.

Yes. Serbian distinguishes aspect.

• dati = perfective, a completed act of giving
• davati = imperfective, repeated or ongoing giving

In this sentence, the meaning is about a single act:

• she wants to give me a dress
• I want to give her a jacket

So dati is the natural choice.

If you used davati, it would sound more like repeated or habitual giving, depending on context.

Also note that after želi da / želim da, both aspects are possible in Serbian, but the choice changes the meaning:

• da da / da dam = to give once, as a completed action
• da daje / da dajem = to be giving, or to give repeatedly/habitually

Here are the main ones:

• ona = she
• želeti = to want
• ja = I
• dati = to give
• haljina = dress
• jakna = jacket
• mi = to me
• njoj = to her

Useful forms from the sentence:

• želi = he/she wants
• želim = I want
• da = to / that; also he/she gives when it is the verb form of dati
• dam = I give
• haljinu = dress, accusative singular
• jaknu = jacket, accusative singular

This sentence is especially useful because it shows several key Serbian patterns at once: da + present, clitic pronouns, dative indirect objects, accusative direct objects, and an irregular verb.