Mais oui is a French phrase that means "but yes" or "of course." It is often used to express agreement or to emphasize that something is obvious. The phrase can be replaced with several synonyms depending on the context and tone of the conversation. For instance, "absolutely" or "definitely" can be used to express strong agreement while "certainly" or "surely" can be used to express less emphasis. Other synonyms for mais oui include "by all means," "without a doubt," and "most certainly." Using synonyms can add a variety of expressions and set one apart in language skills.