The word class that the word in bracket underlined word in the sentence belong to is the adjective.
The adjective is used to modify a noun and give more information about it. Special as used in the sentence means that the pen or brush us used for something different and particularly designed for a unique purpose.
Answer: I think it's incorrect, because they put a comma at the end of her sentence. It had a '...' already there, so why put the comma? Just what I think. I'm not entirely sure, though.
