"Be friendly with" is a common expression used to describe a harmonious and amiable relationship between two individuals. However, there are various synonyms for this phrase that can be used to add variety and depth to one's language. Some examples include: be on good terms with, get along with, be cordial with, be amicable with, have a good rapport with, be companionable with, be affable with, and be sociable with. Each of these synonyms emphasizes a slightly different aspect of a friendly relationship, but all convey a positive and pleasant interaction between people. Using these synonyms can help add nuance and flair to everyday language.