and they are talking. Bob and Mary are laughingand our teacher is walking around the yard barry and mark are playing basketball and writing about everyone in my diary
A simple sentence contains one independent clause with a subject and a predicate. Besides, it makes sense on its own and does not possess any dependent clauses. Thus, even though the subject <em>Joe King</em> is followed by an appositive phrase which identifies him -<em>an engineering professor from California</em>- the sentence still has one single independent clause consisting of a subject and a predicate.
