Questions & Answers about Na obrascu trebaš pisati što urednije.
Na obrascu means on the form.
Croatian often uses na with things like forms, lists, documents, and surfaces where something is written or appears. So you write na obrascu, just as you also get expressions like na papiru (on paper).
Here, obrascu is the locative singular of obrazac (form), because na can take the locative when it means location.
So:
- obrazac = form
- na obrascu = on the form
Using u obrascu would usually not sound natural here, because the idea is not really inside the form in a physical sense, but on it / on the document.