Use Commas Correctly

Use commas to separate items in a series. If more than two items are listed in a series, they should be separated by commas. The final comma the-the one that precedes the word and-is optional (but be consistent throughout your essays).

• CORRECT: My recipe for buttermilk biscuits contains flour, baking soda, salt, shortening and buttermilk.
• CORRECT: My recipe for buttermilk biscuits contains flour, baking soda, salt, shortening, and buttermilk.

Don't place commas before the first element of a series or after the last element.

• INCORRECT: My investment adviser recommended that I construct a portfolio of, stocks, bonds, commodities futures, and precious metals.
• INCORRECT: The elephants, tigers, and dancing bears, were the highlights of the circus.

Use commas to separate two or more adjectives before a noun, but don't use a comma after the last adjective in the series.

• CORRECT: I can't believe you sat through that long, dull, uninspired movie three times.
• INCORRECT: The manatee is a round, blubbery, bewhiskered, creature whose continued presence in American waters is endangered by careless boaters.

Use commas to set off parenthetical clauses and phrases. (A parenthetical expression is one that is not necessary to the main idea of the sentence.)

• CORRECT: Gordon, who is a writer by profession, bakes an excellent cheesecake.

The main idea is that Gordon bakes an excellent cheesecake. The vening clause merely serves to identify Gordon; thus, it should be set with commas.

Use commas after introductory, participial, or prepositional phrases.

• CORRECT: After the banquet, Harold and Martha went dance.

Use commas to separate independent clauses (clauses that could set alone as complete sentences) connected by coordinate conjunctions as and, but, yet, etc.

• INCORRECT: Susan's old car has been belching blue smoke from tailpipe for two weeks, but has not broken down yet.
• CORRECT: Susan's old car has been belching blue smoke from tailpipe for two weeks, but it has not broken down yet.