Punctuation

Each title that follows a name is set off by commas. Incorrect: Kenneth Griffey Jr. could have broken Maris’ record. Correct: Kenneth Griffey, Jr., could have broken Maris’ record. Correct, if pompous: The book was written by John Kenneth Galbraith, A.B., M.A., Ph.D., D.Sc., Litt.D. (Note that each title is set off by commas.) Numerical

Use a comma to separate each part of an address that has two or more parts. This follows the same pattern as geographical names. Commas are not needed if prepositions join the address parts. Incorrect: Write me in care of Post Office Box 203 Shelton Connecticut 06484. (Commas needed) Correct: Write me in care of

Use commas after the salutation (also called the greeting) in a personal letter and after the complimentary closing in all letters. Salutation: Dear Fred, My dearest Emmeline, Closing: Sincerely, Truly yours,

In numbers of more than three digits, use a comma after every third digit from right to left. Incorrect: The area of North America is approximately 9435000 square miles. Correct: The area of North America is approximately 9,435,000 square miles. (This is much easier to read.) Numbers which normally do not take commas are ZIP

Words intentionally left out of clauses may be shown by a comma. A comma is used when the missing words are clearly understood. Incorrect: George liked the color green; John red. (Confusing) Correct: George liked the color green; John, red. (Now missing words are understood.)