Questions & Answers about Njezin peti film je dosadan.
Why do we use peti here instead of pet?
pet is the regular number "five", but peti is the ordinal number "fifth". Because ordinal numbers tell us the order or position of something, they behave just like adjectives in Croatian and must match the noun they describe.
Since peti behaves like an adjective, how would it change for feminine or neuter words?
You change the ending just like you do with a standard adjective. Because film is masculine, we use peti. If you were talking about a "fifth book" (knjiga, which is feminine), it would be peta knjiga. For a neuter word like selo (village), it would be peto selo.
Does njezin (her) take its masculine form because of the woman, or because of the film?
It matches the film. In Croatian, possessive words like njezin must match the gender, number, and case of the thing being owned, not the owner. Since film is a masculine noun in the nominative case, we use the masculine form njezin (you might also see its shorter version, njen).
Why is the word for boring dosadan instead of dosadni?