Agree with is commonly used to express approval of someone else's opinion or statement. However, there are several other synonyms that can be effectively used in place of agree with. Some common alternatives include concur, endorse, support, validate, and acknowledge. Concur suggests that one's own opinion is in line with someone else's, while endorse implies giving one's stamp of approval. Support indicates providing backing to someone else's argument, and validate is a stronger way of indicating agreement. Acknowledge, on the other hand, suggests that one accepts the truth or existence of something. By using these synonyms in place of agree with, one can vary their language and express their agreement in a more subtle way.