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Welcome to Writing Commons, the open-education home for writers. Writing Commons helps students improve their writing, critical thinking, and information literacy. Founded in 2008 by Joseph M. Moxley, Writing Commons is a viable alternative to expensive writing textbooks. Faculty may assign Writing Commons for their composition, business, STEM/Technical Writing, and creative writing courses. 

Writing Commons houses ten main sections: Academic Writing | Rhetoric | Information Literacy | Evidence & Documentation | Research Methods & Methodologies | Style | New Media Communication | Professional & Technical Communication | Creative Writing | Reviews

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What is a colon?

A colon is a punctuation mark used to separate significant parts of a sentence, particularly when the first part offers a sense of anticipation for the second. This form of punctuation is also used in other conventional applications as noted below.

How should colons be used?

How should commas be used?

  • Use commas to separate a series of three or more items, actions, words, or phrases.

    • I will need my backpack, computer, paper, and textbook for my next class.
    • Sharon walked across campus, entered the building, and went to class.
  • Use a comma between coordinating adjectives(closely placed adjectives that are of equal importance and describe the same thing).

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.

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.

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.

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:

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.

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.

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.

Use an apostrophe to denote ownership to a singular or plural noun and indefinite pronoun by adding an -'s if the word doesn't end in -s.

Of all forms of punctuation, the apostrophe appears to be in greatest peril of extinction. For proof that the apostrophe should be placed on an endangered species list in some grammarian's office, one needs only to consult the popular press or a sample of student themes. However, because of its ability to denote ownership in a concise way (by avoiding the use of a preposition), the apostrophe plays an important role in the English language. Despite the frequency of its misuse, the apostrophe is a fairly simple form of punctuation to master.

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 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:

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.

What is a comma splice?

A comma splice is a common sentence problem that occurs when two complete sentences (independent clauses) are incorrectly joined by a comma. This incorrect union of clauses creates a run-on sentence. The problem can be repaired when a different form of punctuation replaces the comma, a coordinating conjunction is inserted, or when the sentence is rewritten.

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 Cesarean 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).

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.

Pronouns are an important part of speech because you use them frequently. And you should use pronouns because they serve important purposes. However, you need to make sure when you use pronouns, you’re using them effectively.

The main purpose of a pronoun is “to replace” a noun. The noun a pronoun replaces is called an antecedent. Pronouns, though, need to be coordinated with their antecedents. If they’re not, confusion quickly emerges for readers.

A pronoun is like a backup quarterback. When the starting quarterback is injured, the backup steps in.

What are pronouns and antecedents?

pronoun is any word that stands in for a previously stated noun, and an antecedent is whatever noun a certain pronoun represents. Using pronouns helps make writing less wordy and repetitive, improving style and expressing the same ideas in fewer words. For example, a piece about “George Washington,” the first president of the United States, does not need to repeat this full name every time it appears, but can instead refer to the antecedent “George Washington” with the pronoun “he”:

When George Washington was asked to run for office, he initially refused.

As a student embarking on your academic career, most papers that you will be asked to write will be academic papers. These academic papers include clear and direct language with a purpose to communicate to your readers your intended message. Clear and direct language should be used to avoid any confusion.

Readers do not want to have to play guessing games with your paper to figure out your main points and arguments, and readers should not have to work hard to figure out what you mean. While much of the success of a well-written essay has to do with having an insightful thesis that is well supported with a cogent synthesis of evidence or sources with appropriate transitions and a logical progression, style and grammar should not be overlooked.

Mechanical issues such as grammatical errors can do more than just make your work appear sloppy: they can even change the meaning of your sentences, thereby confusing your reader. Thus, in the editing stage of the drafting process, it is important to polish your draft for grammatical mistakes and other "local" issues. While the principles discussed in this section are certainly not exhaustive, they address the most common grammatical mistakes found in student writing. Reviewing them in conjunction with other grammar rulebooks will provide you with the necessary tools to conclude your writing project with a clean, polished product.

A single relationship lies at the heart of every sentence in the English language. Like an indivisible nucleus at the center of an atom, the subject-verb pair unifies the sentence. It can be surrounded by any number of modifying words, taking on new shades of meaning, but no matter how many adjectives, adverbs, and independent clauses become attached, the basic unit remains. The subject-verb pair guarantees that the sentence means something. Without this core, a sentence fragments and loses its power to speak. Indeed, a sentence only becomes complete when it contains at least a subject and a verb.

A verb denotes action, existence, or occurrence. A subject denotes the person or thing that performs the action, the person or thing that exists, or the incident that occurs. For example: