Questions & Answers about Ima li on motivacije za projekt?
Why is motivacije in the genitive case here instead of the accusative?
This is the bare partitive genitive. We use it with uncountable nouns to express an unspecified amount, meaning 'some' or 'any'. By putting motivacija (motivation) into the genitive case (motivacije), the sentence naturally translates to 'any motivation' without needing an extra word for 'any'.
Would it be wrong to say Ima li on motivaciju za projekt?
It wouldn't be wrong, but the meaning shifts slightly. Using the accusative (motivaciju) sounds more specific, like asking 'Does he have the motivation?' Using the genitive (motivacije) keeps it broad and uncountable, asking if he has any motivation at all.
Why doesn't the word projekt change its ending after the preposition za?
It actually is in the accusative case, which is required by the preposition za when it means 'for'. However, projekt is a masculine inanimate noun (a thing, not a person or animal). For inanimate masculine nouns, the accusative form looks exactly the same as the nominative dictionary form.