erratic vs changeful

erratic and changeful both are adjectives.

Word	Noun	Adjective	Verb	Adverb
erratic	No	Yes	No	No
changeful	No	Yes	No	No

erratic (adjective)	changeful (adjective)
liable to sudden unpredictable change	such that alteration is possible; having a marked tendency to change
likely to perform unpredictably
having no fixed course