But my book says that they are nouns. "Linguistics is my best subject" is a correct sentence and here Linguistics is a noun, since it is the subject of the sentence. Furthermore, wordreference says "uncountable", so it is a noun.
What about "news"? Is correct: "News says that..."
(that is what my book says, it's written by my teacher -BrE-).
Draughts is damas (el juego de damas).