THE COMMA -- BASIC RULES

Use between words, phrases or clauses in a series.

     Ryan, Stephanie, David, and Carlos went to the beach last week.

     We went over the mountain, beside the river, and through the valley.

     Dave went to London, Carol traveled to Paris, and I stayed home in Monterrey.

Use after a long introductory phrase (5-6+ syllables.)

     During the War of 1812, the issues of the conflict were seldom clear to the soldiers.

     After our Sunday dinner, we often travel to Sta. Catarina to visit Grandma.

Use with appositive phrases

     My friend, David, is captain of the football team.

     The class elected Lucy, the class clown, to be their official representative.

Use with non-restrictive clauses [who, which, that]—(a “non-restrictive clause” is a supporting clause that provides extra or non-essential information.)

     My brother, who works at a bank, thinks that scuba diving is a great sport.

Use to separate independent clauses joined by a coordinating conjunction (F.A.N.B.O.Y.S.!)

     Karen went to the movies, so I decided to hang-out with my friends.

     I really do like this author, but I wouldn’t buy one of his books.

Use to separate dependent and independent clauses in sentences.

     Because David was feeling so good, he got up and cooked breakfast.

     Although the game was far from over, the Rayados were already celebrating!

Use with coordinating adjectives not joined by 'and.'

     Ferocious, alert, loyal dogs were needed badly.

Not with cumulative adjectives:

     The huge old iron lock fell apart.

     TEST: insert 'and' in the above sentence, and it “sounds funny.”

Use with dates, addresses.

     We’re leave on March 17, 2012.

     He lives at Calle Cañon no.422, Col. Del Valle, Monterrey, Nuevo León, Mexico.

Use to separate interjections and direct-address from sentence.

     So, you’re off to see the President?

     I’m telling you, Carl, that you cannot just walk into the President’s office.

Use in conjunction with semi-colon when using conjunctive adverbs.

     The storm was finally passed; however, the rivers were still roaring down the mountain.

     I don’t like to eat meat; nevertheless, I will eat what I’m served at someone’s house.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

THE SEMI-COLON--BASIC RULES

Use a semi-colon to join two related independent clauses.

     Sandra eats mostly junk-food; Kriss prefers fruit and veggies.

     The train’s breaks failed; nothing could stop it now.

Use with conjunctive adverbs.

     The crowd was demanding more food; moreover, they were armed and prepared to fight.