reason vs solve

reason is a noun but solve is not a noun.

Word	Noun	Adjective	Verb	Adverb
reason	Yes	No	Yes	No
solve	No	No	Yes	No

reason (noun)	solve (noun)
the capacity for rational thought or inference or discrimination
a fact that logically justifies some premise or conclusion
a justification for something existing or happening
an explanation of the cause of some phenomenon
a rational motive for a belief or action
the state of having good sense and sound judgment

reason (verb)	solve (verb)
think logically	find the solution to (a problem or question) or understand the meaning of
decide by reasoning; draw or come to a conclusion	find the solution
present reasons and arguments	settle, as of a debt