Does forming a question relies entirely on intonation? For example, "Вона студентка" and "Вона студентка?", like that, same thing?
Victória, adding a question mark or leaving it out completely changes the meaning of the sentence. Without a question mark, it is an authorative statement: she is a student. With a question mark it becomes a question: she is a student? Or: is she a student? Hopefully this helps.