confirm vs substantiate

confirm and substantiate both are verbs.

Word	Noun	Adjective	Verb	Adverb
confirm	No	No	Yes	No
substantiate	No	No	Yes	No

As verbs, confirm and substantiate are synonyms defined as:

confirm and substantiate: establish or strengthen as with new evidence or facts

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

confirm (verb)	substantiate (verb)
make more firm	solidify, firm, or strengthen
establish or strengthen as with new evidence or facts	establish or strengthen as with new evidence or facts
strengthen or make more firm	make real or concrete; give reality or substance to
administer the rite of confirmation to	represent in bodily form
support a person for a position