Moram da završim posao danas.

In modern Serbian, modal verbs like morati usually take a da + present tense clause:

• Moram da završim posao. = I have to finish the job/work.

This pattern is extremely common and natural in everyday Serbian.

You may also hear or see the infinitive after modal verbs:

• Moram završiti posao.

That is also grammatical, but moram da završim is often the more typical conversational choice in many varieties of Serbian.

Because after da, Serbian normally uses a present-tense verb form, not the infinitive.

So:

• infinitive: završiti = to finish
• present form: završim = I finish / I may finish / that I finish, depending on context

In this sentence:

• moram da završim literally works like I must that-I-finish
• natural English: I have to finish

So završim is the correct form after da here.

Završim is 1st person singular present of završiti.

That means it is the form for I:

• ja završim = I finish

In the sentence Moram da završim posao danas, it does not mean simple present in the English sense. After da, it helps express the action that must be done:

• I have to finish the work today.

This is about aspect, which is very important in Serbian.

• završiti = perfective → to finish, to complete
• završavati = imperfective → to be finishing, to finish repeatedly, to work on finishing

In this sentence, the speaker means completing the task as a whole, so the perfective verb is the natural choice:

• Moram da završim posao danas. = I have to get the work finished today.

If you used završavam, it would sound more like focus on the process or a repeated/habitual idea, which does not fit as well here.

Posao is in the accusative singular, which is the normal case for a direct object.

The noun is:

• nominative: posao = work, job
• accusative: posao

For this masculine inanimate noun, the accusative looks the same as the nominative, so the form does not change.

In the sentence:

• završim posao = finish the work/job

That is why posao appears in this form.

It can mean either, depending on context.

• posao can mean job in the sense of employment
• it can also mean work, task, or business

In Moram da završim posao danas, it usually means:

• I have to finish the work today
• or I have to finish the job/task today

So the exact English word depends on the situation.

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

The neutral order here is:

• Moram da završim posao danas.

But you could move elements for emphasis:

• Danas moram da završim posao. = Today I have to finish the work.
• Posao moram da završim danas. = It’s the work that I have to finish today.
• Moram danas da završim posao. = I have to finish the work today.

The meaning stays very similar, but the emphasis shifts.

Putting danas at the end is a very natural, neutral way to add the time phrase.

• Moram da završim posao danas.

This often sounds like the speaker first states the obligation, then adds the important time limit: today.

But Serbian allows other positions too:

• Danas moram da završim posao.
• Moram danas da završim posao.

All are correct; the difference is mainly emphasis and style.

Yes, but that is normal in Serbian.

Serbian often omits subject pronouns because the verb ending already shows the person:

• moram = I must / I have to

So ja is not necessary:

• (Ja) moram da završim posao danas.

You would usually add ja only for emphasis, contrast, or clarity.

A rough pronunciation guide for an English speaker is:

• Moram ≈ MO-rahm
• da ≈ dah
• završim ≈ zah-VR-shim
• posao ≈ PO-sah-o
• danas ≈ DAH-nahs

A few useful sound notes:

• š sounds like sh in ship
• ž sounds like the s in measure
• r in Serbian is usually a trilled or tapped r
• stress is not usually marked in normal writing, so learners often pick it up by listening

Yes, but the meaning changes slightly.

• Moram da završim posao danas. = I have to finish the work today.
  Strong obligation, necessity.

• Treba da završim posao danas. = I should / am supposed to finish the work today.
  Usually softer, more like expectation, recommendation, or plan.

So moram is stronger than treba.

Yes, that is grammatical.

• Moram da završim posao danas.
• Moram završiti posao danas.

Both mean the same thing.

For many learners, da + present is the most useful and productive pattern to master first, because it is extremely common in Serbian. The infinitive version may sound a bit more formal, literary, or regional depending on the speaker and context, but it is still correct.

The infinitives are:

• morati = to have to, must
• završiti = to finish, complete

Relevant present forms:

morati

• ja moram = I have to
• ti moraš = you have to
• on/ona/ono mora = he/she/it has to
• mi moramo = we have to
• vi morate = you have to
• oni/one/ona moraju = they have to

završiti

• ja završim
• ti završiš
• on/ona/ono završi
• mi završimo
• vi završite
• oni/one/ona završe

So the sentence is built as:

• Moram = I have to
• da završim = to finish / that I finish
• posao = the work/job
• danas = today