Prozor se otvaraThe window opensIf something is being done to the word in a sentence without anything or anyone doing it being mentioned, then you also use 'se'. Literally translated the example sentence would be 'The window opens itself'NoteIf something is being done to the word in a sentence without anything or anyone doing it being mentioned, then you also use 'se'. Literally translated the example sentence would be 'The window opens itself'