confirm vs demonstrate

confirm and demonstrate both are verbs.

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

As verbs, demonstrate is a hyponym of confirm; that is, demonstrate is a word with a more specific, narrower meaning than confirm:

confirm: establish or strengthen as with new evidence or facts
demonstrate: establish the validity of something, as by an example, explanation or experiment

Other hyponyms of confirm include back, back up, vouch, verify, establish, prove, shew, show, document, validate.

confirm (verb)	demonstrate (verb)
make more firm	establish the validity of something, as by an example, explanation or experiment
establish or strengthen as with new evidence or facts	provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes
strengthen or make more firm	give an exhibition of to an interested audience
administer the rite of confirmation to	march in protest; take part in a demonstration
support a person for a position