相识

We are only on speaking terms.

Do you know each other?

They met and fell in love when they were college students.

have long been acquainted with each other; have long known each other

meet through a mutual friend

(sth or sb) seem familiar

no discord, no concord; friendship begins after a fight; from an exchange of blows friendship grows

old friend

strike up an acquaintance (with sb)

make sb's acquaintance; make the acquaintance of sb; become acquainted