Questions & Answers about U ovom stupcu treba napisati prezent, a u onom stupcu perfekt.
Treba napisati is an impersonal way to say it is necessary to write, one should write, or in classroom/instruction language, simply write.
Croatian often uses treba + infinitive without naming the person when the instruction is general:
- Treba učiti. = One should study / It is necessary to study.
- Treba odgovoriti na pitanje. = The question should be answered.
In your sentence, the person is understood from context: this is an instruction to the learner.
So:
- U ovom stupcu treba napisati prezent
= In this column, the present tense should be written = more naturally in English, Write the present tense in this column