When we proofread a document, we are looking for small errors such as misspellings or accidental omissions.

Have you ever sent off an email message or submitted a school paper only to later discover that it was full of typographical errors?  How could you have missed all of these errors?

The answer seems to have something to do with how our brains work.  Our brains recognize patterns.  This is part of the reason why people who read frequently tend to read faster than infrequent readers: their brains more speedily recognize and process patterns of words on the page.

Be concise. Once you have written a solid draft, a document that has been well researched, take a step back and question whether or not you can delete half of the words. In a world where billions of instant messages and emails are sent daily, brevity is a virtue. People love conciseness. They respect writers and leaders who can explain difficult matters simply.

Create emphasis and define terms by interrupting the flow of a sentence by using a dash; know when the dash must be used as opposed to the comma.

Some stylists view the dash with great suspicion--the sort of suspicion that a man in the 1990s who wears a plaid leisure suit to work would arouse. Some people erroneously believe that the dash is acceptable only in informal discourse.

However, the dash can provide you with subtle ways to repeat modifiers and dramatic ways to emphasize your point.

Create emphasis and define terms by interrupting the flow of a sentence by using a dash; know when the dash must be used as opposed to the comma.

Some stylists view the dash with great suspicion--the sort of suspicion that a man in the 1990s who wears a plaid leisure suit to work would arouse. Some people erroneously believe that the dash is acceptable only in informal discourse. However, the dash can provide you with subtle ways to repeat modifiers and dramatic ways to emphasize your point.

Use a Dash after a Series or List of Appositives

When you introduce a long series or list of appositives before the subject and verb, you are placing high demands on the reader's short-term memory. Therefore, use this pattern rarely and only for emphasis. This pattern is particularly appropriate in conclusions, when you are bringing together the major threads of your discussion or argument. Finally, you should place a summary word after the dash and preferably before the subject of the sentence, as indicated by the following examples. The most common summary words that writers use are all, those, this, each, what, none, such, these.

  • Jealousy, lust, hate, greed--these are the raw emotions we will explore.
  • Lying, stealing, cheating, committing adultery--which is the greatest sin?
  • To struggle with meaning, to edit, to combine sentences--these activities are well known to the struggling writer.
  • Wining and dining his friends, stroking people's egos, maintaining a good appearance, and spending money--all were part of his scheme to gain influence.

Use Dashes When You Wish to Emphasize a Parenthetical Element

Commas are usually sufficient punctuation to set off parenthetical elements. In some instances, however, you can use a dash instead, especially if you want to make the insertion more noticeable:

  • The building next to ours--the one with the all-cedar exterior--was engulfed in flames.

When you want to whisper rather than shout, you can place the modifiers inside parentheses:

  • The secret I have to tell you (the one I've been hinting about) will surprise you.

Use Dashes to Embed a Series or List of Appositives

A single appositive or modifier can easily be set off from the rest of the sentence in commas, but you must use dashes when you insert a series of appositives or modifiers. After all, how else will the reader know when the series is over?

  • The essential qualities of an effective writer--discipline, effort, inspiration--can be learned by regular writing.
  • With the help of her assistant--a high-speed personal computer--she produced a delightful letter.

Use Dashes to Set off an Emphatic Repetition

You can emphasize an important point by placing a dash or comma at the end of the sentence and then repeating a key word or phrase:

  • Hal is a computer, the ultimate computer.
  • Mrs. Leavitt is a gambler, a compulsive gambler.
  • He was disturbed by the warning--the warning that everyone else ignored.
  • All rapists should be severely punished--punished in a way they will never forget.

Learn how to use proper punctuation.

Below is a summary of how to punctuate different sentence patterns and how to analyze the likely effect of different syntactical forms on readers' comprehension.

Commas: Understand conventions for using commas and appreciate the likely effects of particular sentence lengths and patterns on reading comprehension.
Dashes: Create emphasis and define terms by interrupting the flow of a sentence using a dash; know when the dash must be used as opposed to the comma.
Colons: Use the colon when the first sentence anticipates the second sentence or phrase, thereby creating an emphatic tone.
Semicolons: Use a semicolon to join two sentences or to punctuate a series or list of appositives that already include commas.

Understand conventions for using commas and appreciate the likely effects of particular sentence lengths and patterns on reading comprehension.

Commas are like pawns in chess: They seem relatively insignificant and unobtrusive, yet they are actually very important. If properly placed, the lowly pawn can checkmate the king or, once it has reached the end of the board, become a more powerful piece. Commas play an extremely important role in ensuring that your documents are understandable. In fact, failing to insert a comma in the correct spot can cause considerable misreading (and subsequent embarrassment). Beyond a few special circumstances, there are six basic ways to use commas correctly.

Use Commas to Separate Adjacent Parallel Elements

As demonstrated by the following examples, a series is composed of three or more parallel elements, and the series can appear in the beginning, middle, or end of a sentence:

Stretching, warming up, and cooling down are important to a good exercise program.

All of the necessary qualities of a good assistant -- typing, shorthand, and patience -- she had in abundance.

The three qualities of a good introduction are context, purpose, and organization.

Editors and grammarians are in sharp disagreement about whether a comma should be placed before the last element in a series. The trend in the popular press is not to include the comma if the elements in the series are brief. However, many well-known stylists have persuasively argued that conjunctions connect and commas separate, so it is incorrect in their opinion to judge the comma as redundant punctuation before a conjunction such as "and." In addition, uninformed readers may perceive the last two elements in the series to be a compound if the comma is omitted. For example, placement of the comma before the word "and" in the following example makes it clear that flowering plants are not the same as ornamental bushes:

The landscaping contract includes several exotic plants, ornamental bushes, and flowering plants.

Occasionally, as dictated by your ear and the rhythm you hope to establish, you may want to insert a comma and forgo the and, as in this example:

We have a government of the people, by the people, for the people.

When you want to slow down the rhythm of your sentence and emphasize a point, you can replace all the serial commas with and or or:

He does not like shrimp or crayfish or lobster or anything that turns red when cooked.

If the abuse of the wetlands continues, we will be without waterfowl and fish and wildlife.

When you must present a long array of parallel elements in your documents, you can avoid listing them by grouping them into logical parts and punctuating accordingly, as demonstrated by the following examples:

Writing is painful and exhilarating, tedious and inspiring, chaotic and planned.

Human activities such as coal and oil burning, population growth and increased food demands, clearing and burning forests have caused increases in the release of carbon dioxide and methane.

Finally, note that coequal, consecutive coordinate adjectives that modify the same noun should generally be separated with commas:

Although he appears to have your best interests in mind, he truly is a competitive, combative, cantankerous boss.

However, you should not separate two consecutive adjectives with commas if the first adjective is modifying both the following adjective and noun as a unit, as illustrated below:

The competitive track star runs forty miles a week.

Use Commas to Join Two or More Independent Clauses

In most instances, place a comma between two sentences that are joined with a coordinating conjunction--and, but, or, for, nor, so, yet:

She was not sure if she had the necessary mathematical abilities to be an engineer, so she pursued a graduate degree in history.

He was surrounded by fifty people, yet he felt all alone.

You do not need to place a comma between two independent clauses if they are short and similar in meaning, provided that no misunderstanding will take place, as illustrated in the following example:

Some doctors advertise their services but many doctors find this reprehensible.

The absence of the comma in this sentence is acceptable; it is not necessary to prevent misreading.

Use Commas after Introductory Subordinate Clauses

To avoid confusion, use a comma after an introductory subordinate clause or phrase:

Because the costs of conducting research continue to increase, we need to raise our rates.

As the shrimp boats trawl, sea grass can collect on the trap door, allowing shrimp to escape.

According to the professor, rich women are more likely to have caesarean sections than poor women.

In keeping with the modern trend toward using as little punctuation as possible, some stylists believe that it is not necessary to place a comma after short introductory words (now, thus, hence) and phrases (In 1982 he committed the same crime). However, conservative style manuals still call for the comma, so you are better off playing it safe and placing a comma after introductory words and clauses.

Use a Comma After Conjunctive Adverbs and Transitional Phrases at the Beginnings of Sentences

Although our modern style calls for using as few commas as possible, you should generally place a comma after conjunctive adverbs and transitional words because they modify the entire sentence:

Nevertheless, we must push forward with our plans.

In other words, you're fired. Hey, I'm just kidding.

Because commas cause readers to pause in their reading, you want to use them sparingly. Although logic would suggest that it makes sense to follow coordinating conjunctions with commas, convention does not call for this usage unless the conjunction is followed by an introductory phrase. Thus, it would he inappropriate to write:

Yet, I think we should go ahead as planned.

When a short phrase follows the conjunction at the beginning of the sentence, however, it is appropriate--although not absolutely necessary--to place a comma after the conjunction:

Yet, as I mentioned yesterday, I think we should go ahead as planned.

Use Commas Around Nonrestrictive Parenthetical Elements

You should limit the number of times that you interrupt the flow of a sentence by placing modifying words between the subject and its verb. When you do introduce such appositives, participial phrases, or adjective phrases or clauses, you must determine whether the modifiers are restrictive or nonrestrictive. Essentially, restrictive modifiers add information that is essential to the meaning of the sentence, whereas nonrestrictive modifiers add information that is not essential. The best way to determine whether a modifier is restrictive or nonrestrictive is to see if taking it out changes the meaning of the sentence.

Restrictive: Lawyers who work for McGullity, Anderson, and Swenson need to take a course in copyediting.

In this case the relative clause is essential to the meaning of the sentence. If you embedded the clause in commas, then the meaning would change, suggesting that all lawyers need a course in copyediting.

Restrictive: The lawyer who has worked on this case for three years thinks that we have no chance of winning.

In this case the relative clause is essential to the meaning of the sentence. In other words, the sentence refers to only the lawyer who has worked on this case. The discussion is restricted to her.

Nonrestrictive: The lawyers, who have an office downtown, think that we have no chance of winning.

Because the location of the lawyer's office is superfluous to the gist of the sentence, it should be set off by commas.

Use Commas Before Nonrestrictive Adverbial Phrases or Clauses at the Ends of Sentences

At the end of your sentence, you need to be especially careful about where you place your commas. In particular, you need to question whether the modifying words are restrictive or nonrestrictive. For instance, suppose you received a memo from your writing instructor that said,

You should revise the essay, as I suggested.

You could assume that you were directed to revise the essay in any way you deem appropriate. However, if the instructor omitted the comma, then you would be receiving an entirely different message: revise the essay exactly as prescribed by the instructor.

Below are some additional sentences to give you a sense of how to determine whether your modifying words are restrictive or nonrestrictive:

Nonrestrictive: Reports indicate that a Turtle Excluder Device (TED) costs from $85 to $400, depending on the model.

Restrictive: Writers can change readers' outlooks on issues provided that they offer sufficient evidence.

In this case, a comma after issues could suggest that writers have numerous ways to change readers' opinions and that one of these methods is providing sufficient evidence. In contrast, the lack of a comma means that providing evidence is the one criterion writers need to follow.

Use a semicolon to join two sentences or to punctuate a series or list of appositives that already includes commas.

The semicolon offers a "higher" form of punctuation than the comma or dash. Unlike commas or dashes, the semicolon can correctly be used to separate sentences. If readers tend to pause for a half-second when they come to a comma, they pause for three-quarters of a second when they reach a semicolon. Writers use semicolons two major ways.

Use a Semicolon to Join Two Sentences

You can show that ideas are closely related by using a semicolon rather than a period between them.

  • The secretary's fingers burned across the typewriter; the financial statements would be picked up by the client in one hour.
  • The question, though, is not economics; it is professional objectivity.
  • Breast cancer used to be the biggest killer for women; now it's lung cancer.

Use a Semicolon to Punctuate a Series or List of Appositives That Already Includes Commas

When elements in a series require internal commas to ensure clarity, then semicolons must be used to separate those elements:

  • A perfect vacation would be long, relaxing, and cheap; include personable, sweet, flexible people; and make everything else seem trivial.
  • The delegates were from Sacramento, California; Jacksonville, Florida; Providence, Rhode Island; and Ann Arbor, Michigan.
  • A good proofreader must have good grammar, punctuation, and spelling skills; must like to read; and must have patience.

Note, however, that you are wise to avoid using unnecessary semicolons. Experienced writers and readers would prefer the second sentence because it avoids self-conscious punctuation.

  • He was dressed in white pants; a white, Mexican wedding shirt; and sandals.
  • He was dressed in a white, Mexican wedding shirt, white pants, and sandals.

Use the colon when the first sentence anticipates the second sentence or phrase, thereby creating an emphatic tone.

The colon provides a dramatic and somewhat underutilized way to bring a little spark to your writing. Beyond normal business correspondence (Dear Sir or Madam:), you can use the colon before quotations, formal statements and explanations. The colon enables you to highlight a semantic relationship--that is, a movement from a general statement to a specific clarification. The colon also provides a dramatic way to tease the reader's curiosity:

  • As a modern ordeal by torture, litigation excels: It is exorbitantly expensive, agonizingly slow, and exquisitely designed to avoid any resemblance to fairness or justice.