Lesson Ten

Mastering Punctuation

Punctuation has been called, aptly, the “print code.” Punctuation helps us signal in print the kinds of things we signal with voice patterns and intonation and with facial expressions and body movements, when we speak. Unless we master the print code, our writing is severely impoverished-just as our speech would be impoverished if we couldn’t vary our vocal patterns or facial expressions or body movements (sort of like Al Gore).

First, a word about what punctuation does not include. It does not include use of capital letters, italics, underlining, boldface, or varying font sizes, shapes, or styles. True, we use these things to signal, in print, some of the things traditionally signaled by punctuation. This has become more common as personal computers, with their many visual options, have flooded the world. The line between text and image has never been a sharp one, and computers have blurred it even further. One of the most amusing examples of this is pictures made of type-mostly punctuation marks!-used now in millions of email messages.

But there is still such a thing as the traditional print code, punctuation, and its exclusive application to text. Punctuation shows the parts and edges of sentences; that is its grammatical function. But punctuation also creates or reinforces psychological aspects of our sentences. That is its stylistic function.

Let’s now look at some of the most important, and most troublesome, aspects of the print code. In this unit, you’ll improve your mastery of the following kinds of punctuation:

o Commas
o Colons
o Semicolons
o Dashes
o Ellipses
o Hyphens
o Parentheses
o Quotation marks

The trickiest, and probably the most important piece of punctuation, is the comma. That’s because, of all the punctuation marks, it’s the one most used not just to help signal grammatical features of sentences, but to help create rhythm and style. Sometimes you must use a comma or you’ll drastically mislead your reader. Sometimes a comma isn’t necessary, but it’s helpful. In other instances, you’ll want to take “poetic license,” inserting or omitting a comma to achieve some desired effect. But remember: you can’t break rules intelligently until you master them.

Let’s review how to use commas correctly and how some people (not you) use them incorrectly. I’m going to blast through a long list of rules, so hold on.

Use commas to

1. Introduce words and phrases:
Unfortunately, the experiment failed.
After a long period in the red, ACME emerged into the black.

2. Join compound sentences:
Both occupants of the car were wearing seat belts, so injuries were minimal.
They finished writing the proposal, and that was all they could manage before collapsing.
Bruno bench pressed 500 pounds, yet he himself weighed a mere 395.

3. Set off nonrestrictive elements (including appositives):
Galapagos tortoises live to be about 200, which is an impressive life span.
The Whisper 2000, a rotary engine, is quiet and economical.

4. Set off interjected and transitional elements:
The president of the United States is elected, believe it or not, via the electoral college.
Weld power wiring, therefore, requires more than a 2″ conduit.

5. Separate items in a series:
We bought nuts, bolts, wires, tape, and bandages.
Radionuclides have hurt our herons, mutilated our mink, wounded our walleye, traumatized our trout, and brutalized our beavers.

NOTE: It’s an excellent idea to include that final comma just before the “and.” Many people leave it out, sometimes creating an ambiguity, as in “He took courses in math, science, economics and architecture of Medieval Europe.” This leaves the reader wondering whether “economics and architecture of Medieval Europe” is one course or two.

6. Set off direct address and “tag questions”:
Look into your hearts, members of the jury, and find compassion there.
Detaching the blue wire disarms the bomb, doesn’t it?

7. Set off quotations:
As the saying goes, “Old fishermen never die; they just smell that way.”
[But don't use a comma if your sentence introduces the quotation with "that," or if your quotation is indirect or just part of a longer construction]:

The adage says that “old fishermen never die; they just smell that way.”

People who ask “How are you?” really just mean “Hello.”

8. Set off dates, addresses, and titles:

The product must ship by June 12, 2001.

Seattle, Washington is called the Emerald City.

Fred Thompson, M.D., performed the surgery.

9. Avoid confusion and awkward-looking prose:

The members of the committee walked in, in time to vote.


The members of the committee walked in in time to vote.

Before, they had believed the containers to be full of harmless sludge.


Before they had believed the containers to be full of harmless sludge.

FYI, don’t use commas

10. To introduce or finish a series:

Wrong: We ordered a mix, of soybeans, corn, wheat, and rice.

Right: We ordered a mix of soybeans, corn, wheat, and rice.

Wrong: I’ve always wanted a big, expensive, loaded, computer.

Right: I’ve always wanted a big, expensive, loaded computer.

11. In compound constructions:

Wrong: Safe drinking water, and clean air are essential to health.

Right: Safe drinking water and clean air are essential to health.

Wrong: The field is infested with grasshoppers, and Japanese beetles.

Right: The field is infested with grasshoppers and Japanese beetles.

12. Around restrictive elements:

Wrong: This is the switch, that starts the engine.

Right: This is the switch that starts the engine.

13. Between subjects and verbs, verbs and objects (or compliments), prepositions and verbs:

Wrong: The mercury model, considers both organic and inorganic mercury.

Wrong: The mercury model considers, both organic and inorganic mercury.
Wrong: The fish ate, about a barrel of feed per day.

14. Between independent clauses:

Data gathering has always been a primary component of regulatory programs, it is a given that we will ask corporations and businesses for data.

Note: placing commas between independent clauses (full sentences) produces the infamous comma splice. An easy fix is to change the comma to a semicolon, or link the two sentences with a coordinating conjunction (and, or, for, but, so, yet), or just end one sentence with a period and start a new sentence. But don’t choose one of these options arbitrarily. Choose according to your rhetorical purpose. If, for example, you wish to reinforce a cause-effect relationship between two sentences, you may want to join them with a semicolon rather than chopping them into two distinct sentences. More on this shortly.

Using Commas Rhetorically

Choosing punctuation according to rhetorical purpose means that you punctuate in order to achieve some psychological effect. For example: a sentence reads faster with minimal punctuation. Punctuation-laden sentences read more slowly. Sometimes, you’ll want to speed up or slow down your reader. If you want to convey a sense of urgency or speed or rushed confusion, you can intensify this effect via punctuation (or lack thereof):

The investors want to see our phone transcripts and email and memos and maps and sketches and figures and projections before they’ll even begin to consider our proposal.

BTW, you may feel a temptation to underline or italicize begin. Resist it. Trust your reader. You’ve already set up the sentence in such a way that emphasis must (must) fall on that word.

Now let’s try slowing down a sentence:

Vehicle congestion is terrible, particularly in communities like this, where urban sprawl, unplanned, and the need to commute, unavoidable, combine, every weekday morning, to produce sluggish caravans of coughing, creeping autos.

Did you feel yourself sputtering and creeping along in that sentence, like those poor autos? Good. That’s what I intended you to feel.

Normally, however, you won’t want to slow down your reader that much. But you will certainly want her to pause or mentally “breathe” at chosen spots in your sentence. It’s best to “feel” those spots yourself, as you’re writing, and insert the commas as you go (rather than backtracking to pepper them in later). Take scientist-writer Lewis Thomas’s advice:

The commas are the most useful and usable of all the stops. It is highly important to put them in place as you go along. If you try to come back after doing a paragraph and stick them in the various spots that tempt you you will discover that they tend to swarm like minnows into all sorts of crevices whose existence you hadn’t realized and before you know it the whole long sentence becomes immobilized and lashed up squirming in commas. Better to use them sparingly, and with affection, precisely when the need for each one arises, nicely, by itself.


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