QUESTION: Can a simple sentence have 2 verbs with a same subject and two subjects with the same verb? For instance, My friend and I were sitting in the library and studying for our exam.
ANSWER: The simple answer is yes. Your example above has a compound subject and a compound verb. It is not a compound sentence, however, because it is still a single independent clause. A simple sentence becomes a compound sentence when it is joined to an independent clauses. (See https://www.ellcenter.com/academy/writing-handouts/sentences/)