corroborate vs affirm

corroborate and affirm both are verbs.

Word	Noun	Adjective	Verb	Adverb
corroborate	No	No	Yes	No
affirm	No	No	Yes	No

As verbs, corroborate and affirm are synonyms defined as:

corroborate and affirm: establish or strengthen as with new evidence or facts

Other synonyms of corroborate include confirm, substantiate, support, sustain.

corroborate (verb)	affirm (verb)
establish or strengthen as with new evidence or facts	establish or strengthen as with new evidence or facts
give evidence for	to declare or affirm solemnly and formally as true
support with evidence or authority or make more certain or confirm	say yes to