Paraphrased from Warriner’s English Grammar and Composition, Fifth Course The Comma

Use commas to separate items in a series Ex: the guidance counselor recommended that I take English, algebra, chemistry, and French. Ex: Will you spend your vacation in the mountains, on the lake, or at the shore?

Use commas to separate two or more adjectives that modify the same noun Ex: She is a young, dynamic, and creative woman.

Use a comma before and, but, or, nor, for, yet when they join independent clauses. Ex: We subscribe to seven magazines, and I find it impossible to read each one every month. Ex: Mr. Ballin is a popular teacher, for he is known to be fair, and he has a sense of humor.

Use commas to set off nonessential clauses and nonessential participial phrases. Ex: Margaret Mead, who is a disciple of Ruth Benedict, is a noted anthropologist.

Use a comma after certain introductory elements. After words such as well, yes, no, why, etc when they begin a sentence Ex: Why, I can’t believe it! Ex: No, it’s impossible to leave now. Ex: Well, I will think it over. Ex: Yes, I can join you tomorrow. After an introductory participial phrase Ex: Struck by lightening, the ancient oak tree crashed to the ground. After a succession of introductory prepositional phrases Ex: During the first half of our trip down the Mississippi, all five of us were seasick. After an introductory adverb clause Ex: Because the magazine sometimes contains clever satires and parodies, we sometimes read it in English class.

Use commas to set off expressions that interrupt the sentence. Appositives ( a word – with or without modifiers - that follows a noun or pronoun and identifies it or explains it.) Ex: Have you met Mr. Lauro, our new Spanish teacher? Words in direct address Ex: Helen, did you hear what I said? Ex: I know, Ramon, that you will do well. Ex: What is your chief complaint, children?

Parenthetical expressions A word or phrase that may serve as explanation or qualification, but does not affect the grammatical construction of the sentence. oAfter all oAs a matter of fact oBy the way oConsequently oFor example oHowever oI believe/hope/think oIncidentally oIn fact oIn the first place oNaturally oNevertheless oOn the other hand otherefore Ex: As a matter of fact, I was just going to call you. Ex: That is, of course, only one option.

Use a comma in certain conventional situations. To separate items in dates and addresses Ex: The reunion was held on Wednesday, June 16, After the salutation of a friendly letter and the closing of any letter Ex: Dear Rosa, Ex: Sincerely yours,

Do not use unnecessary commas.