Colons & Semicolons

COLONS (:)

Colons can be used to introduce a list, an appositive, or a formal quotation. Colons are always used after an independent clause

Lists

The colon comes after an independent clause and before the items listed.

I have several favorite sports: baseball, football, basketball, and hockey.
I have four classes on Mondays: Biology, Chemistry, English, and Art.

Note: Not all lists need colons. For instance, a writer should not use a colon before a list if the part before it cannot be a complete sentence.

I bought: bagels, milk, and cereal. = NOT CORRECT
("I bought" cannot be a complete sentence.)

I bought bagels, milk, and cereal. = CORRECT
(Since the items in the list are essential to complete the sentence, do not use a colon. Commas are appropriate in this list.)

I bought breakfast foods: bagels, milk, and cereal. = CORRECT
(The items after the colon are not essential to finish the sentence, but they do describe what breakfast foods were bought. "I bought breakfast foods” is a complete sentence and can stand on its own.)

Appositives

Appositives are nouns or pronouns that rename or modify the nouns they follow. Notice in the following examples how the clause before the colon is a full sentence.

My goal is simple: win the lottery.
Only one person is not invited to the party: my crazy brother, Fred.

Quotes

Colons can be used to introduce formal (and often, lengthy) quotations.

Martin Luther King, Jr. inspired his listeners at the Lincoln Memorial on August 28, 1963: ''And so even though we face the difficulties of today and tomorrow, I still have a dream...It is a dream deeply rooted in the American Dream. I have a dream that one day this nation will rise up and live out the true meaning of its creed: ‘We hold these truths to be self-evident, that all men are created equal.’[...] I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character. I have a dream today!"

SEMICOLONS (;)

Semicolons are used primarily for two reasons: to separate or to connect.

Lists

If items in a list have commas within, semicolons are used to separate the bigger items to avoid confusion.

My best friends are Sarah, the consultant, Tom, the construction worker, Lilly, the high school teacher, and Mike, the writer. = NOT CORRECT
(It is confusing whether Sarah or Tom is the consultant, etc.)

My best friends are Sarah, the consultant; Tom, the construction worker; Lilly, the high school teacher; and Mike, the writer. = CORRECT
(To show that "the consultant" is describing Sarah and "the construction worker" is describing Tom, we can use semicolons to separate the bigger items in the list.)

Sentences

Semicolons can show a connection between closely related sentences. A period could be used instead of a semicolon, but the direct connection might be lost.

People often misjudge this restaurant; though the paint on the outside of the building is old and chipped, the décor and food are amongst the best in the city.

Clauses on both sides of the semicolon must be complete sentences.

When the general walked in; everyone stood up. = NOT CORRECT
(The beginning phrase, “When the general walked in,” cannot be its own sentence.)

When the general walked in, everyone stood up; he was a man who commanded respect. = CORRECT
(The semicolon comes between two independent clauses that can stand alone but are thematically related.)