for sure vs unquestionable

for sure and unquestionable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
for sure	No	Yes	No	Yes
unquestionable	No	Yes	No	No

for sure (adjective)	unquestionable (adjective)
not open to doubt	incapable of being questioned
	not counterfeit or copied
	not open to question

for sure (adverb)	unquestionable (adverb)
definitely or positively (`sure' is sometimes used informally for `surely')