Affirm

verb

1. To agree, verify or concur; to answer positively.

   "She affirmed that she would go when I asked her."

2. To assert positively; to tell with confidence; to aver; to maintain as true.
3. To support or encourage.

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

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