Sentence:  Moreover, this relationship is a <WSD>productive</WSD> one, in the sense that when new Adjectives are created (e.g. "ginormous" concocted out of "gigantic" and "enormous"), then the corresponding Adverb form (in this case "ginormously") can also be used. And in those exceptional cases where Adverbs do not end in "-ly", they generally have the same form as the corresponding Adjective, as with "hard", "fast", etc. 
Meaning of the word marked with <WSD> tags:  Consistently applicable to any of an open set of words.