The word 赞同 is formed by combining two independent characters, each contributing its core meaning to create a new, unified concept. The first character, 赞, carries the sense of "to praise" or "to endorse". The second, 同, means "same", "together", or "to agree". Their combination does not follow a strict action-subject pattern but rather merges these ideas into a single, nuanced verb meaning "to approve of and agree with", effectively capturing the act of giving one's supportive agreement.