Breakdown of Prijateljica ju danas treba.
danas
today
trebati
to need / should (ought to)
prijateljica
friend (f)
ju
her (accusative clitic)
Questions & Answers about Prijateljica ju danas treba.
Why is ju placed right after Prijateljica?
ju is an accusative clitic pronoun. Clitics are short, unstressed words that must follow a strict rule: they almost always take the second position in a sentence. Here, it correctly sits directly after the first word, Prijateljica.
Could I change the word order and say Prijateljica danas treba ju?
No, that would be grammatically incorrect. Because ju is a clitic, it is locked into the second position. You could, however, say Prijateljica ju treba danas, which keeps the clitic in second place but slightly changes the emphasis at the end of the sentence.
I learned that the short word for 'her' is je. Why is it ju here?
ju is an alternative form of the short (clitic) pronoun for 'her'. While je is the standard default, ju is extremely common in everyday Croatian. It is mandatory when the verb je (is) is right next to it to avoid saying je je, but many people also use it freely as a substitute in sentences like this one.
How do we know who needs who? Could this mean 'She needs the friend'?
We know the friend is the one doing the needing because Prijateljica is in the nominative (subject) case. The pronoun ju is in the accusative (object) case, which tells us 'her' is the person receiving the action.