swear vs affirm

swear and affirm both are verbs.

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

As verbs, swear and affirm are synonyms defined as:

Other synonyms of swear include assert, aver, avow, swan, verify.

swear (verb)	affirm (verb)
have faith or confidence in	establish or strengthen as with new evidence or facts
make a deposition; declare under oath	to declare or affirm solemnly and formally as true
utter obscenities or profanities	say yes to
promise solemnly; take an oath
to declare or affirm solemnly and formally as true