A compound sentence contains two independent clauses joined by a coordinator. The coordinators are as follow: for, and, nor, but, or, yet, so. (Helpful hint: The first letter of each of the coordinators spells FANBOYS.) Except for very short sentences, coordinators are always preceded by a comma.
A. I tried to speak Spanish, and my friend tried to speak English.
B. Alejandro played football, so Maria went shopping.
C. Alejandro played football, but Maria went shopping.
The above sentences are compound. Each sentence contains two independent clauses, and they are joined by a coordinator with a comma preceding it. Note how the conscious use of coordinators can change the relationship between the clauses. Sentences B and C, for example, are identical except for the coordinators. In sentence B, which action occurred first? Obviously, “Alejandro played football” first, and as a consequence, “Maria went shopping. In sentence C, “Maria went shopping” first. and consequently “Alejandro played football” because, possibly, he didn’t have anything else to do, for or because ”Maria went shopping.” How can the use of other coordinators change the relationship between the two clauses? What implications would the use of “yet” or “but” have in the meaning of the sentence?