Uses of colons and semicolons

When to use a Semicolon A semicolon is used to link two complete sentences without a conjunction such as and or but. You can always use a period and start a new sentence instead of using a semicolon, but when your sentences are closely related or continue the same thought, it helps the reader to have a semicolon.

Example: I’m going to the grocery store; I need to buy bananas.

If you use a comma instead of semicolon, this is called a comma splice. It is incorrect. Incorrect example: I’m going to the grocery store, I need to buy bananas.

You should also use a semicolon when you link two complete sentences with a conjunctive adverb such as however, therefore, or nevertheless. Example: I wanted to go to the beach today; however, I have to go to work. Notice that the semicolon comes before the conjunctive adverb, and a comma follows the conjunctive adverb. It is important to get this punctuation correct.

Semicolons can also be used in a list where commas are already present. Example: My road trip will take me to the following destinations: San Diego, California; Portland, Oregon; Flagstaff, Arizona; and Nashville, Tennessee.

When to Use a Colon

There are two main uses for the colon in everyday writing. Both require an independent clause, also known as a complete sentence, before the colon. The first use is when introducing a list, and the second is when introducing an explanation or example.

Example: I need to pick up a few things at the grocery store: milk, bread, cheese, and juice. Example: After 10 hours of deliberation, the jury made its decision: the defendant was guilty.

Incorrect example: My favorite places to shop are: the mall, the local shopping center, and the Internet. The last example was incorrect because the colon was not preceded by a complete sentence. In this case, you would not need any punctuation. Just write the list.

A colon tells the reader that what follows is closely related to the preceding clause. The colon has more effect than the comma, less power to separate than the semicolon, and more formality than the dash.

A colon may introduce a quotation that supports or contributes to the preceding clause. Example: The squalor of the streets reminded her of a line from Oscar Wilde: “We are all in the gutter, but some of us are looking at the stars.”

The colon also has certain functions of form: to follow the salutation of a formal letter, to separate hour from minute in a notation of times, and to separate the title of a work from its subtitle or a Bible chapter from a verse.

Examples Dear Mr. Montague: departs at 10:48 P.M Practical Calligraphy: An Introduction to Italic Script Nehemiah 11:7