7.2 Semicolons, Colons, and Dashes

Semicolons: Connecting Closely Related Ideas

The semicolon is a punctuation mark that often intimidates writers, but its rules are actually quite straightforward. A semicolon represents a pause that is longer than a comma but shorter than a period. On the ACCUPLACER exam, the primary use of a semicolon is to join two independent clauses that are closely related in meaning.

Joining Independent Clauses

An independent clause can stand alone as a complete sentence. When you have two independent clauses that discuss the same topic or are logically connected, you can join them with a semicolon instead of a period. This creates a smoother transition and emphasizes the relationship between the two ideas.

Example: The museum exhibition was a resounding success; thousands of visitors attended on the opening weekend.

Student Trap: A common mistake is using a semicolon to join an independent clause with a dependent clause. A semicolon must have a complete sentence on both sides. If one side is a fragment, the semicolon is incorrect.

• Incorrect: Even though the weather was terrible; the outdoor festival continued as planned.
• Correct: Even though the weather was terrible, the outdoor festival continued as planned.

Semicolons with Conjunctive Adverbs

Sometimes, you may want to connect two independent clauses using a conjunctive adverb (such as however, therefore, moreover, or nevertheless) or a transitional phrase (such as in addition or as a result). When you do this, you must place a semicolon before the conjunctive adverb and a comma after it.

Example: The company's profits have decreased significantly this quarter; therefore, management has decided to implement cost-cutting measures.

Semicolons in a Complex List

While commas are typically used to separate items in a series, a semicolon is required when the items in the series themselves contain commas. This helps prevent confusion by clearly marking the boundaries of each item.

Example: The conference attendees came from Paris, France; London, England; and Berlin, Germany.

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Colons: Introducing and Expanding

The colon is a punctuation mark of anticipation. It signals to the reader that what follows will explain, illustrate, or fulfill the promise of what came before it. The most important rule for using a colon is that the words preceding it must form a complete, independent clause.

Introducing Lists

A colon is frequently used to introduce a list of items, provided that the introductory text is a complete sentence.

Example: The hikers packed several essential items for their trek: a map, a compass, extra water, and a first-aid kit.

Student Trap: Do not use a colon if the list immediately follows a verb or a preposition. The clause before the colon must be able to stand alone.

• Incorrect: The necessary ingredients are: flour, sugar, and butter.
• Correct: The necessary ingredients are flour, sugar, and butter.
• Correct: We need the following ingredients: flour, sugar, and butter.

Introducing Explanations or Amplifications

A colon can also be used to separate two independent clauses when the second clause explains, illustrates, or expands on the first clause. In this usage, the colon acts like the phrase "that is to say."

Example: The team faced one major obstacle: they lacked the necessary funding to complete the project.

Introducing Quotations

When you introduce a long or formal quotation with a complete sentence, use a colon to separate the introduction from the quotation.

Example: The CEO's message to the shareholders was clear and uncompromising: "We must prioritize sustainable growth over short-term profits."

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Dashes: Emphasizing and Interrupting

The em dash (—) is a versatile and dramatic punctuation mark. It is longer than a hyphen and is used to create a strong break in a sentence, often for emphasis or to set off interrupting information.

Setting Off Nonessential Information

Like commas and parentheses, dashes can be used to set off nonessential clauses or phrases. While commas provide a neutral pause and parentheses de-emphasize the information, dashes draw attention to the enclosed text, making it stand out.

Example: The new software—which took over two years to develop—finally launched yesterday.

When using dashes to set off information in the middle of a sentence, you must use a pair of dashes. If the information comes at the end of the sentence, use a single dash.

Example: Only one person knew the combination to the safe—the manager.

Indicating a Sudden Break or Change in Thought

Dashes are excellent for capturing a sudden shift in tone, a self-correction, or an abrupt change in the direction of a sentence.

Example: I was planning to finish the report tonight—wait, did you say the deadline was moved to next week?

Punctuation Usage Chart

To help you differentiate between these marks, consider this comparison:

Passage-Based Editing Example: Original text: The scientist made a groundbreaking discovery, she identified a new microorganism capable of breaking down plastic waste. Correction: The original sentence contains a comma splice, joining two independent clauses with only a comma. To emphasize that the second clause explains the discovery mentioned in the first, a colon or a semicolon would be appropriate. "The scientist made a groundbreaking discovery: she identified a new microorganism capable of breaking down plastic waste."

By mastering the rules for semicolons, colons, and dashes, you will be well-equipped to handle the punctuation questions on the ACCUPLACER exam and add variety and precision to your own writing.