spontaneously vs spontaneous

spontaneously is not an adjective while spontaneous is an adjective.

Word	Noun	Adjective	Verb	Adverb
spontaneously	No	No	No	Yes
spontaneous	No	Yes	No	No

spontaneously (adjective)	spontaneous (adjective)
	happening or arising without apparent external cause
	said or done without having been planned or written in advance

spontaneously (adverb)	spontaneous (adverb)
in a spontaneous manner
without advance preparation