Colons are used to introduce detailed lists or phrases and to show relationships between numbers, facts, words, and lists.
Identify sentences that require colons
- A colon can introduce the logical consequence, or effect, of a previously stated fact.
- A colon can introduce the elements of a set or list.
- Colons separate chapter and verse numbers in citations of passages in widely studied texts, such as epic poetry, religious texts, and the plays of William Shakespeare. A colon can also separate the subtitle of a work from its principal title.
- Colons may also separate the numbers indicating hours, minutes, and seconds in abbreviated measures of time.
- Sometimes, a colon can introduce speech or dialogue.
- enumeration: A detailed account in which each thing is noted.
- appositive: A word or phrase that is placed with another as an explanatory equivalent.
Using Colons in Sentences
Some punctuation marks, such as periods, question marks, and exclamation points, indicate the end of a sentence. However, commas, semicolons, and colons all can appear within a sentence without ending it.
The colon has a wide range of uses. The most common use is to inform the reader that whatever follows the colon proves, explains, defines, describes, or lists elements of what preceded the colon. Essentially, sentences that are divided by colons are of the form, “Sentence about something: list or definition related to that sentence.”
In modern American English usage, a colon must be preceded by a complete sentence with a list, a description, an explanation, or a definition following it. The elements that follow the colon may or may not be complete sentences. Because the colon is preceded by a sentence, it is a complete sentence whether what follows the colon is another sentence or not.
In American English, many writers capitalize the word following a colon if it begins an independent clause —that is, a clause that can stand as a complete sentence. The Chicago Manual of Style, however, requires capitalization only when the colon introduces speech or a quotation, a direct question, or two or more complete sentences.
Other Uses of the Colon
In addition to being used in the middle of sentences, colons can also be used to visually separate information.
Separating Chapters and Verses
A colon should be used to separate chapter and verse numbers in citations of passages in widely studied texts, such as epic poetry, religious texts, and the plays of William Shakespeare.
- Example: John 3:14–16 refers to verses 14 through 16 of chapter three of the Gospel of John.
Separating Numbers in Time Abbreviations
- Example: The concert begins at 11:45 PM.
- Example: The rocket launched at 09:15:05 AM.
Separating Titles and Subtitles
An appositive colon also separates the subtitle of a work from its principal title.
- Example: Star Wars Episode IV: A New Hope
Similar to a dash and a quotation mark, a segmental colon can introduce speech.
- Example: Benjamin Franklin proclaimed the virtue of frugality: “A penny saved is a penny earned.”
This form can also be used in written dialogues, such as plays. The colon indicates that the words following an individual’s name are spoken by that individual.
- Example: Patient: Doctor, I feel like a pair of curtains. Doctor: Pull yourself together!
Semicolons are used to link related clauses and to separate information in lists that contain additional punctuation.
Identify when and how to use semicolons properly
- Semicolons connect two closely related, independent clauses (complete sentences) and turn them into a single sentence.
- Semicolons take the place of periods or commas followed by coordinating conjunctions (FANBOYS: for, and, nor, but, or, yet, so).
- Semicolons should be used before conjunctive adverbs (however, meanwhile, therefore, otherwise, in addition, and others) to link together sentences. Follow conjunctive adverbs with a comma.
- Semicolons can be used in lists that include lots of commas.
- conjunctive adverbs: These words are preceded by a semicolon and followed by a comma. There is a long list, but here are some examples: however, meanwhile, in addition, and therefore.
- dependent clause: This group of words also contains a subject and/or verb, but do not create a complete, stand-alone sentence.
- coordinating conjunction: Simple words that connect two independent clauses together or connect an independent clause to a dependent clause (sentence fragment). They are remembered by the acronym FANBOYS.
- independent clause: A group of words that contains a subject (noun) and a verb and can stand as a complete sentence.
Semicolons link together independent clauses that are closely related, making them flow into a single sentence. Often, using a period to separate related sentences makes them seem choppy. A semicolon is an alternative to using a period or a comma plus coordinating conjunction. Semicolons used before conjunctive adverbs also replace periods. It is important to understand that using a semicolon in place of a period fuses two independent clauses into one; therefore, make sure you don’t start the second independent clause with a capital letter. The final use of semicolons is to separate items in a list or series with lots of commas or other punctuation.
Linking Independent Clauses
Semicolons can be used to join closely related, independent clauses. There are three ways to link independent clauses: with a period, a semicolon, or a comma plus coordinating conjunction (FANBOYS).
- With a period: John finished his homework. He forgot to pass it in.
- With a semicolon: John finished his homework; he forgot to pass it in.
- With a comma plus a coordinating conjunction: John finished his homework, but he forgot to pass it in.
Remember, use of a semicolon is only appropriate if the sentences have a strong relationship to each other.
Independent Clauses Linked with Conjunctive Adverbs
Semicolons can also be used between independent clauses linked with a conjunctive adverb. Follow the conjunctive adverbs with a comma. This usage is very formal, and is typically found in academic tests.
- Example: Everyone knows he committed the crime; accordingly, we expect the jury to agree on a guilty verdict.
- Example: The students failed to finish their in-class assignment; therefore, they are required to remain after school.
Listing Items in a Series
Semicolons are used between items in a list or series when those items themselves contain internal punctuation.
- Example: Several fast-food restaurants can be found within the following cities: London, England; Paris, France; Dublin, Ireland; and Madrid, Spain.
- Example: Here are three examples of familiar sequences: one, two, three; a, b, c; first, second, third.
- Example: Dental hygienists perform clerical jobs such as bookkeeping, answering phones, and filing; administrative jobs such as filing out insurance claims and maintaining patient files; and clinical jobs such as making impressions of the teeth and gums, taking x-rays, and removing sutures.
Formatting with Semicolons
Semicolons are typically followed by a lowercase letter, unless that letter is the first letter of a proper noun like “I” or “Paris.” In some style guides, such as APA, however, the first word of the joined independent clause should be capitalized.
Modern style guides recommend no space before semicolons and one space after. Modern style guides also typically recommend placing semicolons outside of ending quotation marks.