In sentence 1 quickly shows how or in what manner Juma runs that is quickly modifies the verb runs In sentence 2 very shows how much or to what degree the mango is sweet that is very modifies the adjective sweet In sentence 3 quite shows how far or to what extent Jane reads clearly that is quite modifies the adverb clearly A word that that modifies a verb an adjective or another adverb is called an adverb