Juče sam kupila novine u prodavnici.

This is the past tense in Serbian. It is normally made with:

• the present tense of biti (to be)
• plus the past active participle

So:

• sam = I am / auxiliary used for I in the past tense
• kupila = bought (feminine singular form)

Together, sam kupila means I bought.

Because the speaker is female.

In Serbian, the past participle agrees with the subject in gender and number:

• kupio sam = I bought (male speaker)
• kupila sam = I bought (female speaker)
• kupili smo = we bought (mixed group or all male)
• kupile smo = we bought (all female)

So kupila tells you that the person speaking is a woman.

Because sam is a clitic, and Serbian clitics usually go in the second position in the sentence or clause.

So in:

• Juče sam kupila novine u prodavnici.

the first element is Juče, and the clitic sam comes right after it.

This second-position pattern is very important in Serbian. That is why:

• Juče sam kupila... sounds normal
• Juče kupila sam... sounds wrong or very unnatural

You may also hear:

• Kupila sam novine juče.

There, Kupila is the first element, so sam comes after it.

Juče means yesterday.

It does not change the tense grammatically by itself, but it gives a clear time reference. The verb is already in the past tense because of sam kupila.

So:

• Juče = yesterday
• sam kupila = I bought

Together: Yesterday I bought...

This is a very common question. In Serbian, novine is grammatically plural, but it often means newspaper in the everyday sense.

So:

• novine literally looks like newspapers
• but in many contexts it means a newspaper

This is similar to how some nouns in other languages behave as plural in form but singular in meaning.

If the sentence means buying one newspaper, Serbian still commonly says:

• kupila sam novine

If you want to make it more explicit, context usually does the job.

Because after u meaning in, Serbian usually uses the locative case when talking about location.

The base form is:

• prodavnica = shop, store

The locative singular is:

• u prodavnici = in the shop / in the store

So:

• u + locative = in, at a location

Compare:

• u prodavnici = in the store
• u školi = in school
• u gradu = in the city

It can mean either, depending on context.

Literally, u prodavnici means in the store, but in natural English translation it may also be rendered as at the store.

Serbian often uses u where English might choose either in or at, depending on what sounds more natural in English.

Kupiti is perfective.

That means it presents the action as completed: the buying happened and was finished.

So sam kupila here suggests:

• I bought it / I finished the act of buying

The imperfective partner is usually:

• kupovati = to be buying / to buy habitually / to buy over time

Compare:

• Juče sam kupila novine. = Yesterday I bought the newspaper/newspapers.
• Juče sam kupovala novine. = Yesterday I was buying newspapers / I spent time buying newspapers.

In this sentence, the perfective verb is the normal choice for a single completed action.

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

So:

• novine can mean a newspaper, the newspaper, or newspapers
• prodavnici can mean in a store, in the store, or in stores, depending on context

The exact meaning is usually understood from the situation, previous conversation, or general context.

A man would say:

• Juče sam kupio novine u prodavnici.

The only change is:

• kupila → kupio

That is because the past participle changes for the speaker’s gender.

It can be rearranged, because Serbian word order is fairly flexible. But the clitic sam still has to follow the first element.

Possible versions include:

• Juče sam kupila novine u prodavnici.
• Novine sam kupila juče u prodavnici.
• U prodavnici sam juče kupila novine.
• Kupila sam novine juče u prodavnici.

These versions may shift focus or emphasis, but they all can mean roughly the same thing.

The main thing to remember is the placement of sam.

A rough English-friendly pronunciation is:

• YOO-cheh sam KOO-pee-lah NOH-vee-neh oo proh-dahv-NEE-tsee

A few useful sound notes:

• j is like English y
• č sounds like ch in church
• c sounds like ts
• lj, nj, ć, đ are special Serbian sounds, though they do not appear here except č

So:

• Juče sounds roughly like YOO-cheh
• prodavnici ends with -tsi

It is in the accusative, because it is the direct object of kupila.

You are buying what?

• novine

For this noun, the accusative plural has the same form as the nominative plural:

• novine = nominative plural
• novine = accusative plural

So even though the form does not change, its role in the sentence is accusative because it is the object of the verb.