Use a comma to separate two independent clauses when they are joined by one of seven coordinating conjunctions (for, and, nor, but, or, yet, so). We were out of ice cream, so I went to the store. (c) ...

DEAR RICHARD: The Oxford comma, also known as the serial comma, is the comma used before the conjunction in a list of three or more items. For example: “I like to eat apples, bananas, and oranges.” I ...