Questions & Answers about Ovaj problem je velik, ali imamo plan.
Because problem is a masculine noun in Croatian. Demonstratives agree with the noun’s gender, number, and case:
- masculine: ovaj problem
- feminine: ova knjiga (book)
- neuter: ovo pitanje (question)
It’s nominative singular, because it’s the subject of the sentence: Ovaj problem je velik = This problem is big.
In predicate position (after je = is), Croatian very commonly uses the short (indefinite) adjective form:
- Problem je velik. (predicative → short form)
The long/definite form (veliki) is more typical before a noun:
- veliki problem = a/the big problem
(You may still hear Problem je veliki in some contexts/dialects, but Problem je velik is the standard “textbook” choice.)