Finding it interesting that the 'een' is required here, but not with Nederlander or Amerikaan.
Een is not required here, and have just fixed it.
Without een you indicate someones Nationality, with een you emphasise more a specific person (same with professions).
Is "Spanjaard" or "Spaanse" the more common translation for "Spaniard"?
'Spanjaard' is a man, and 'Spaanse' is a woman.
In the other quiz, I wrote she is "a spanish" and i got a wrong answer SMH.
Because in English you cannot say: (s)he is a spanish.