Questions & Answers about Hladno je, zato mi treba kaput.
Because hladno here is not describing a noun. It is being used in an impersonal expression meaning it is cold.
In Serbian, weather and general conditions are often expressed this way:
- Toplo je. = It is warm.
- Hladno je. = It is cold.
- Mračno je. = It is dark.
So hladno functions like an adverbial/predicative form, not like an adjective agreeing with a person or thing.
By contrast, hladan is an adjective and would describe a masculine noun:
- Kaput je hladan. = The coat is cold.
- On je hladan. = He is cold / emotionally cold, depending on context.
Je is the 3rd person singular present form of biti (to be).
So hladno je literally means something like cold is, but naturally it means it is cold.
Serbian often leaves out the equivalent of English it in weather or general-condition sentences. English needs a dummy subject (it is cold), but Serbian does not.
Zato here means therefore, so, or .