Comma Rules

1. Comma Rules The comma is the most frequently used punctuation mark.

2. Comma Rule 1 Use a comma in a compound sentence to separate two independent clauses linked by a coordinating conjunction (and, or, nor, but, so, for, yet).

3. Use a comma with a conjunction to join independent clauses • Incorrect: The mixture was prepared from the two premixes and the remaining ingredients were then combined. • Correct: The mixture was prepared from the two premixes, and the remaining ingredients were then combined.

4. Comma Rule 2 • Use a comma to separate items in a series composed of three or more elements. • Correct: The manager of spare parts is responsible for ordering, stocking, and disbursing all spare parts for the entire plant.

5. Comma Rule 3 • Use a comma to separate introductory words, phrases, and clauses from the main clause of a sentence.

6. Use a comma to separate introductory words, phrases, and clauses from the main clause. • Correct: However, we will have to calculate the effect of the wind. • Correct: To facilitate trade, the government holds a yearly international conference.

7. Comma Rule 4 • Use a comma to separate a dependent clause from the main clause.

8. Use a comma to separate a dependent clause from the main clause. • Although most of the executive council saw nothing wrong with it, the advertising campaign was cancelled. • Most PCs use green technology, even though it is relatively expensive.

9. Comma Rule 5 • Use commas to separate nonrestrictive modifiers (parenthetical clarifications) from the rest of the sentence. These nonrestrictive modifiers are sometimes called appositives. • Correct: Jones, the temporary chairman, called the meeting to order.

10. Use commas to separate nonrestrictive modifiers (parenthetical clarifications) from the rest of the sentence • Incorrect: The phone line which was installed two weeks ago had to be disconnected. • Correct: The phone line, which was installed two weeks ago, had to be disconnected.

11. Comma Rule 6 • Use a comma to separate interjections and transitional elements from the rest of the sentence.

12. Use a comma to separate interjections and transitional elements from the rest of the sentence • Yes, I admit that your findings are correct. • Their plans, however, have great potential.

13. Comma Rule 7 • Use a comma to separate coordinate adjectives. • The finished product was a sleek, comfortable cruiser. • The heavy, awkward trains are still being used.

14. Note: Use the comma to replace the word ‘and.’ If ‘and’ doesn’t fit, don’t use a comma. • They decided to go to the first general meeting. • Hand me the reversible electric drill.

15. Comma Rule 8 • Use a comma to signal that a word or phrase has been omitted from a sentence because it is implied. • Smithers is in charge of the accounting; Harlen, the data management; Demar, the publicity.

16. Comma Rule 9 • Use a comma to separate a proper noun from the rest of the sentence in direct address. • John, have you finished your project? • What I’d like to know, Betty, is why we didn’t see this problem coming.

17. Comma Rule 10 • Use a comma to introduce most quotations: • He asked, “What time are they expected?”

18. Comma Rule 11 • Use a comma to separate towns, states, and countries. • Manhattan, Kansas, is the original site of Kansas State University. • Oxford, England, is the home of Oxford University.

19. Comma Rule 12 • Use a comma to set off the year in a date: • August 1, 2007, is the anticipated completion date. • You do not use a comma if the month separates the day and year: • The anticipated completion date is 1 August 2007.

20. Comma Rule 13 • Use a comma to separate numbers: • The answer is 12,013,104. • I will need $12,976 to close the deal.

21. Comma Rule 14 • Use a comma to separate names from professional or academic titles: • Harold Clayton, Ph.D. • Marion Fewick, CEO • Note: the comma also follows the title in a sentence: • John Dunn, Ph.D, is the featured speaker.

22. Unnecessary Commas • Writers often introduce errors by using unnecessary commas. Do not insert comma in the following situations:

23. Do not use comma splices. • Commas are not used to link two independent clauses without a coordinating conjunction. • Incorrect: The cars were all washed, the newest models were parked in the garage.

24. Commas are not used to separate the subject from the verb of a sentence. • Incorrect: Another of the many possibilities, is to use a “first in, first out” sequence. • Correct: Another of the many possibilities is to use a “first in, first out” sequence.

25. Commas are not used to separate the verb from its complement. • Incorrect: The schedules that have to be updated every month are, numbers 14, 16, 21, 22, 27, and 31. • Correct: The schedules that have to be updated every month are numbers 14, 16, 21, 22, 27, and 31.

26. Commas are not used with a restrictive modifier. • Incorrect: New and old employees, who use the processed order form, do not completely understand the basis of the system. • The phrase ‘who use the processed order form’ is a restrictive modifier necessary to the meaning: it defines which employees do not understand the system.

27. Incorrect: A company, that has grown so big, no longer finds an informal evaluation procedure effective. • Correct: A company that has grown so big no longer finds an informal evaluation procedure effective.

28. Commas are not used to separate two elements in a compound sentence. • Incorrect: Recent studies, and reports by other firms, confirm our experience. • Correct: Recent studies and reports by other firms confirm our experience.

29. Go and commit comma sins no more! • If you are still confused as to when you should use or not use a comma, follow this simple rule: If in doubt, leave it out!