how does adding an "-er" to a verb change its part? (A) it makes a verb an adjective (B) it makes a verb an adverb (C) it makes a verb a noun (D) it makes a verb a pronoun​
It makes the verb an adjective because if you have "fast" and put in "-er" you'd get "faster". Faster would mean going more vigoriously than before, therefore describing the speed of "fast"
