affirm

To agree, verify or concur; to answer positively.

She affirmed that she would go when I asked her.

To assert positively; to tell with confidence; to aver; to maintain as true.

Jesus, […] whom Paul affirmed to be alive

However, as anyone who knew Adrian Shooter would affirm, he very rarely took no for an answer.

To support or encourage.

gender-affirming; trans-affirming

They did everything they could to affirm the children's self-confidence.

To make firm; to confirm, or ratify; especially (law) to assert or confirm, as a judgment, decree, or order, brought before an appellate court for review.

To state under a solemn promise to tell the truth which is considered legally equivalent to an oath, especially of those who have religious or other moral objections to swearing oaths; also solemnly affirm.

Yes; true; correct.