en penna - a pen pennor - pens pennan - the pen pennorna - the pens en maskin - a machine maskiner - machines maskinen - the machine maskinerna - the machines

pennor is the plural, indefinite form of penna and pennorna is the plural, definite form of penna en penna: a pen pennan: the pen pennor: pens pennorna: the pens It is the same to the latter case.