When a sentence has two or more subjects, that's called a “compound subject.” The individual subjects in a compound subject are joined by a coordinating conjunction (and, or, neither, nor). When the subjects are joined by “and,” the verb agrees with the pronoun “they.” Joanie and Chachi love each other. © @google
The examples are:
Joana and Marie are friends
Bea and Sha were cooking.
(Just think two subjects and include "and" (coordinating conjunction) )