doubtful vs uncertain

doubtful and uncertain both are adjectives.

Word	Noun	Adjective	Verb	Adverb
doubtful	No	Yes	No	No
uncertain	No	Yes	No	No

doubtful (adjective)	uncertain (adjective)
open to doubt or suspicion	not established beyond doubt; still undecided or unknown
fraught with uncertainty or doubt	lacking or indicating lack of confidence or assurance
unsettled in mind or opinion	not certain to occur; not inevitable
	not established or confirmed
	ambiguous (especially in the negative)
	not consistent or dependable
	subject to change