Otkazali smo koncert.

Because Serbian often leaves subject pronouns out when they are already clear from the verb form.

In Otkazali smo koncert, the combination -li + smo already tells you the subject is we. So mi is not necessary.

You could say Mi smo otkazali koncert, but that usually adds emphasis, like we cancelled the concert.

It is the past tense in Serbian.

Serbian forms this tense with:

• a past participle form: otkazali
• plus a present-tense form of to be: smo

So:

• otkazali = cancelled
• smo = are / we are, but here it functions as part of the past tense

Together, otkazali smo means we cancelled or we have cancelled, depending on context.

That ending agrees with the people who did the action.

In this sentence, otkazali is the masculine plural form, which is also the normal form for:

• a group of men
• a mixed group of men and women
• a group whose gender is not being specified

If the speakers were all female, you would say:

• Otkazale smo koncert.

Compare:

• Otkazao sam koncert. = I cancelled the concert. (male speaker)
• Otkazala sam koncert. = I cancelled the concert. (female speaker)
• Otkazali smo koncert. = We cancelled the concert. (masculine or mixed group)
• Otkazale smo koncert. = We cancelled the concert. (all-female group)

Koncert is the direct object here, so it is in the accusative case.

But for many masculine inanimate nouns, the accusative singular looks exactly the same as the nominative singular. That is why you see:

• koncert → koncert

So even though the case has changed grammatically, the form stays the same.

A useful comparison:

• Vidim koncert. = I see the concert.
• Vidim čoveka. = I see the man.

Here čoveka changes because čovek is masculine animate, while koncert does not change because it is masculine inanimate.

Because smo is a clitic in Serbian. Clitics usually cannot stand at the very beginning of a sentence. They tend to go in the second position of the clause.

That is why Otkazali smo koncert is natural:

• Otkazali = first element
• smo = clitic in second position

You can also say:

• Mi smo otkazali koncert.
• Koncert smo otkazali.

But Smo otkazali koncert is not normal standard word order.

Yes. Serbian word order is more flexible than English, although not completely free.

These are all possible, with different emphasis:

• Otkazali smo koncert. = neutral
• Mi smo otkazali koncert. = emphasizes we
• Koncert smo otkazali. = emphasizes the concert

What usually stays true is that the clitic smo wants to be near the beginning, typically in second position.

So word order can change for emphasis, but not randomly.

The basic verb is otkazati, and here it is perfective.

That means it presents the action as a completed whole: the cancellation happened as a finished event.

Its imperfective partner is usually otkazivati.

Very roughly:

• otkazati = to cancel, as a completed act
• otkazivati = to be cancelling / to cancel repeatedly or in an ongoing sense

So Otkazali smo koncert uses the perfective idea: the concert was cancelled.

It can mean either one in English.

Serbian past tense often covers both:

• a simple past meaning: we cancelled the concert
• a present-relevant meaning: we have cancelled the concert

The exact English translation depends on context. Serbian does not force the same distinction that English sometimes does.

Yes. In this sentence, koncert is the direct object — it is the thing being cancelled.

The structure is:

• Otkazali smo = we cancelled
• koncert = the concert

So the sentence is built like verb + object, even though the Serbian past tense is expressed with two parts.

Serbian does not have articles like English the and a.

So koncert can mean:

• a concert
• the concert

The context tells you which one is meant.

That is why Otkazali smo koncert can translate as either:

• We cancelled a concert
• We cancelled the concert

In real situations, context usually makes it obvious.