demonstrative vs informative

demonstrative is a noun but informative is not a noun.

Word	Noun	Adjective	Verb	Adverb
demonstrative	Yes	Yes	No	No
informative	No	Yes	No	No

demonstrative (noun)	informative (noun)
a pronoun that points out an intended referent

demonstrative (adjective)	informative (adjective)
given to or marked by the open expression of emotion	providing or conveying information
serving to demonstrate	tending to increase knowledge or dissipate ignorance
	serving to instruct or enlighten or inform