Moja sestra sada radi, ali sutra nije na poslu.

to be

Breakdown of Moja sestra sada radi, ali sutra nije na poslu.

• raditi: to work
• sada: now
• ne: not

Questions & Answers about Moja sestra sada radi, ali sutra nije na poslu.

Why is it moja sestra and not moj sestra?

Because moja must agree with sestra in gender, number, and case.

• sestra is feminine singular
• so the possessive my becomes moja

Compare:

• moj brat = my brother
• moja sestra = my sister
• moje dete = my child

So moja sestra is the correct feminine form.

What exactly does radi mean here?

Radi is the 3rd person singular present tense of raditi.

Here it means:

• works
• or is working

In Serbian, the present tense often covers both:

• a general/habitual meaning: She works
• an action happening now: She is working

Because the sentence also includes sada (now), the meaning is clearly She is working now.

Why doesn’t Serbian use a separate form for is working, like English does?