1) Adjective modifiers 2) Duly and truly 3) Hither and yon 4) How words 5) Now and then 6) Now, never, etc 7) Parts of speech 8) Purely and simply 9) Quickly and slowly, for two 10) Slowly and surely 11) Some modifiers 12) Tom Swifty words 
a word which modifies a verb, an adverb, or an adjective