Commas: stoplights in the traffic of your writing
• Punctuation marks such as commas are signposts used to construct and support the meaning of your writing. Commas serve as interrupters or signals to the reader to pause.
• If those signposts are missing, your meaning is obstructed, and misunderstandings may lead to collisions of thought in the mind of your reader.

The Dramatic Pause
Theory
• Do not place commas according to where you, the writer, would pause.
• Instead, place commas according to the following guidelines, which signal the reader to pause.

Use commas to separate sentence tags from the rest of the sentence.
• He’s going to Rome in August, isn’t he?
• It doesn’t have four legs, does it?
• You skipped class today, didn’t you?
• I had a car accident, that’s why.

• Use a comma to separate parenthetical words, phrases, or clauses from the rest of the sentence.
• A parenthetical element— an interrupter—is a word or word group that often interrupts your sentence and may be omitted without affecting the meaning of the sentence.

More commas with parenthetical elements and interrupters
– Don’t forget to place commas before and after the interrupter!
• Traffic signal management, on the whole, has been a problem on campus.
• The Sabaru Justy, it seems, is very much like the Ford
Festiva.
• The cafeteria menu, in fact, has a variety of items.
• Barbara Jordan is, in my opinion, a prolific and eloquent orator.
• We will, of course, honor Dr. Brown posthumously and present the award to his widow after the service.

Commas with conjunctive adverbs
• Common conjunctive adverbs include however, therefore, thus, for example, moreover, nevertheless, and furthermore ; moreover, their purpose is to mark a shift or contrast in the sentence.
• Use commas to separate them from the rest of the sentence:
– You are, moreover, entirely correct in your statement.
– Today, we cross the country in a few hours by plane; however, our ancestors spent months making the trip in covered wagons.
– Thus, the Gothic novel has supernatural, ghostly, and mysterious themes.

• We will therefore, have to operate.
• The meeting on the whole went well.
• He has, in fact been missing for three days.
• The dog however lost its bone in the fight.
• You missed your doctor’s appointment didn’t you?
• As time passed furthermore Mike made many enemies.
• I will of course complete the graduation requirements this spring semester.

• We will, therefore, have to operate.
• The meeting, on the whole, went well.
• He has, in fact, been missing for three days.
• The dog, however, lost its bone in the fight.
• You missed your doctor’s appointment, didn’t you?
• As time passed, furthermore, Mike made many enemies.
• I will, of course, complete the graduation requirements this spring semester.