Moja majka sada radi u banci.

Because moja has to agree with majka in gender, number, and case.

• majka is feminine
• singular
• here it is in the nominative case because it is the subject of the sentence

So the possessive adjective must also be feminine singular nominative:

• masculine: moj
• feminine: moja
• neuter: moje

That is why you get moja majka = my mother.

Both can mean mother / mom, but they are used a little differently.

• majka is more neutral or formal
• mama is more affectionate and everyday, like mom / mum

So:

• Moja majka sada radi u banci. sounds neutral
• Moja mama sada radi u banci. sounds more personal and conversational

Both are correct.

Radi is the 3rd person singular present tense of the verb raditi = to work.

The present-tense pattern is:

• ja radim = I work
• ti radiš = you work
• on/ona/ono radi = he/she/it works

Since moja majka is she, the verb form is radi.

It can mean both, depending on context.

In Serbian, the present tense often covers both:

• a general fact: My mother works in a bank
• a current situation: My mother is working in a bank now

The word sada helps suggest now, so in this sentence the meaning is closer to is now working or now works.

Because after u meaning in / at for location, Serbian uses the locative case.

The base noun is:

• banka = bank

In the locative singular, it becomes:

• u banci = in/at the bank

So:

• banka = dictionary form
• u banci = location form after u

This is a very common pattern with feminine nouns ending in -a.

It changes because of the locative singular ending.

For many feminine nouns ending in -a, the ending changes to -i in the locative:

• škola → u školi
• kuća → u kući
• banka → u banci

Also, notice the consonant change:

• k often changes to c before i

So:

• banka
• stem changes before the ending
• banci

This is a normal sound/spelling change in Serbian.

It can mean any of those, depending on context.

Serbian has no articles like a or the, so banci does not itself tell you whether the meaning is:

• in a bank
• in the bank
• at a bank
• sometimes even at the bank

You understand that from the situation, not from the noun form alone.

Because Serbian often does not need subject pronouns when the subject is already clear.

Here, the subject is explicitly given as:

• moja majka

So there is no need to add ona = she.

Also, the verb form radi already shows 3rd person singular, so Serbian can often leave pronouns out unless they are needed for emphasis or contrast.

Yes. Serbian word order is fairly flexible.

The neutral order here is:

• Moja majka sada radi u banci.

But other orders are possible, for example:

• Sada moja majka radi u banci.
• Moja majka radi sada u banci.
• U banci moja majka sada radi.

These versions can sound more marked, focused, or stylistically different. The original sentence is a natural, neutral way to say it.

Sada means now, and in this sentence it comes after the subject:

• Moja majka sada radi u banci.

That placement is very natural. It often sounds like:

• topic: my mother
• new information/time frame: now
• main action: works
• place: in a bank

You can move sada for emphasis, but the original position is one of the most neutral choices.

Literally, u banci means in/at a bank.

In real usage, though, it often naturally means working at/for a bank, just like English can say She works in a bank even if the important idea is her place of employment, not the physical interior of the building.

So Serbian uses u banci very naturally here.

A simple pronunciation guide is:

• Moja ≈ MOH-ya
• majka ≈ MY-kah
• sada ≈ SAH-dah
• radi ≈ RAH-dee
• u ≈ oo
• banci ≈ BAHN-tsee

A few useful sound notes:

• j is pronounced like English y in yes
• c is pronounced like ts
• stress in Serbian is not usually marked in normal spelling, so learners often imitate it best by listening to native audio

Yes. Sad is a very common short form of sada.

So both are correct:

• Moja majka sada radi u banci.
• Moja majka sad radi u banci.

The shorter sad is especially common in everyday speech.