Why isn't it "donderdag is geen maand"?
"Donderdag is geen maand" is far more common...
I thought they aren't interchangeable. Isn't it incorrect to replace "geen" with "niet een"?
I think that with niet you are stressing the "is" so therefore "is niet" while with geen you are stressing the worth "month" (which is not a verb, therefore using the word geen)
But I'm still a nooobie so don't take what I say for granted
You don't say.