choose vs purchase

choose is not a noun while purchase is a noun.

Word	Noun	Adjective	Verb	Adverb
choose	No	No	Yes	No
purchase	Yes	No	Yes	No

choose (noun)	purchase (noun)
	the acquisition of something for payment
	the mechanical advantage gained by being in a position to use a lever
	a means of exerting influence or gaining advantage
	something acquired by purchase

choose (verb)	purchase (verb)
pick out, select, or choose from a number of alternatives	obtain by purchase; acquire by means of a financial transaction
see fit or proper to act in a certain way; decide to act in a certain way
select as an alternative over another