Moj otac nosi košulju na poslu.

Because moj must agree with otac in gender, number, and case.

• otac = father
• It is masculine singular
• Here it is in the nominative case because it is the subject of the sentence

So the correct form is:

• moj otac = my father

If the noun were feminine, you would use moja, for example:

• moja majka = my mother

Otac is in the nominative singular.

That is the basic dictionary form, and it is used here because my father is the one doing the action.

In this sentence:

• Moj otac = the subject
• nosi = wears / is wearing
• košulju = shirt
• na poslu = at work

So otac stays in the nominative because it is the subject.

Nosi is the 3rd person singular present tense of the verb nositi.

Here it means:

• wears
• sometimes also is wearing, depending on context

So Moj otac nosi košulju na poslu can mean something like:

• My father wears a shirt at work
• or My father is wearing a shirt at work

Serbian present tense often covers both a general habit and a present situation, and context tells you which one is meant.

Because košulju is the accusative singular form of košulja.

• košulja = shirt, blouse
• košulju = shirt/blouse as the direct object

The verb nositi takes a direct object, so the noun has to go into the accusative:

• košulja → nominative
• košulju → accusative

This is very common with feminine nouns ending in -a:

• knjiga → knjigu
• torba → torbu
• košulja → košulju

Because na poslu is a fixed and very common Serbian expression meaning at work.

Breakdown:

• na = on / at
• poslu = the locative singular of posao (job, work)

After na, Serbian often uses the locative when talking about location:

• na poslu = at work
• na fakultetu = at the faculty / at college
• na stolu = on the table

So even though English says at work, Serbian idiomatically says na poslu.

Because after na in a location meaning, Serbian uses the locative case.

The noun is:

• posao = job, work

Its locative singular form is:

• poslu

So:

• na poslu = at work

This is one of those forms you simply get used to with declension. The noun changes because its role in the sentence changes.

Serbian does not have articles like English a/an and the.

So košulju by itself can mean:

• a shirt
• the shirt

The exact meaning depends on context.

In a sentence like this, English might translate it either way depending on the situation:

• My father wears a shirt at work
• My father is wearing the shirt at work

Serbian speakers usually do not need an article, because the meaning is clear from context.

No, Serbian word order is fairly flexible, although Moj otac nosi košulju na poslu is the most neutral order.

This sentence follows a basic pattern:

• subject: Moj otac
• verb: nosi
• object: košulju
• adverbial phrase: na poslu

You can move things around for emphasis, for example:

• Na poslu moj otac nosi košulju.
• Košulju moj otac nosi na poslu.

These are grammatically possible, but they change the focus or emphasis. For a learner, the original order is the safest and most natural neutral choice.

Yes. You could say:

• Otac nosi košulju na poslu.

But that usually means father in a more general or context-dependent way, and it may sound less natural unless it is already clear whose father you mean.

Using moj makes it explicit:

• moj otac = my father

So moj is not required by grammar in every sentence, but it is needed if you want to clearly say my father.

No. Nositi has a broader meaning than just to wear.

It can also mean:

• to carry
• to bear
• to take
• to wear clothing

Examples:

• Nosi torbu. = He/She is carrying a bag.
• Nosi košulju. = He/She is wearing a shirt.

So in this sentence, the object košulju tells you that nosi means wears / is wearing.

These are two sounds that English speakers often ask about.

• š is like sh in shoe
• lj is a single Serbian sound, similar to the lli in million for many English speakers, though not exactly the same

So košulju is approximately pronounced like:

• ko-SHOO-lyu

That is only an approximation, but it helps.

Also:

• j in Serbian is pronounced like English y in yes

So lju sounds roughly like lyu.

Yes. That is a very important point.

The Serbian present tense can describe:

• a general habit
• a repeated action
• something happening now

So Moj otac nosi košulju na poslu can mean:

• My father wears a shirt at work — habitual
• My father is wearing a shirt at work — current situation

Usually the surrounding context tells you which meaning is intended.