Formal:
* Approve: This is the most direct and neutral word.
* Endorse: This implies a strong support, often publicly.
* Sanction: This suggests official approval or authorization.
* Commend: This means to praise someone or something.
* Affirm: This indicates a firm confirmation or acceptance.
Informal:
* Like: This is a casual way to express approval.
* Love: This implies a strong liking.
* Appreciate: This suggests gratitude or recognition of value.
* Agree: This indicates concurrence with an opinion or proposal.
* Thumbs up: This is a gesture of approval.
Other options:
* Praise: This refers to expressing admiration or approval.
* Compliment: This means to express praise or admiration.
* Support: This implies backing or encouragement.
* Favor: This indicates a positive opinion or attitude.
The best word to use depends on the specific situation and the level of approval you want to express.