alter vs alterable

alter is not an adjective while alterable is an adjective.

Word	Noun	Adjective	Verb	Adverb
alter	No	No	Yes	No
alterable	No	Yes	No	No

alter (adjective)	alterable (adjective)
	capable of being changed or altered in some characteristic
	(of the punishment ordered by a court) capable of being changed to one less severe

alter (verb)	alterable (verb)
remove the ovaries of
become different in some particular way, without permanently losing one's or its former characteristics or essence
cause to change; make different; cause a transformation
insert words into texts, often falsifying it thereby
make an alteration to