swear vs assure

swear and assure both are verbs.

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

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

Other hyponyms of swear include hold, claim, take, attest, declare, protest, tell.

swear (verb)	assure (verb)
have faith or confidence in	be careful or certain to do something; make certain of something
make a deposition; declare under oath	inform positively and with certainty and confidence
utter obscenities or profanities	assure somebody of the truth of something with the intention of giving the listener confidence
promise solemnly; take an oath	make a promise or commitment
to declare or affirm solemnly and formally as true	make certain of