Section 15.5 The Colon
The colon establishes a directional relationship: what comes before it is a complete sentence that anticipates something, and what comes after it delivers that something—a list, an explanation, a restatement, or a clarification. The grammatical rule: the material before the colon must be a complete independent clause.
Introducing Lists.
Use a colon after a complete sentence to introduce a list:
-
Please bring the following items: a pen, a notebook, and a calculator.
Do not use a colon after an incomplete sentence:
-
Please bring: a pen, a notebook, and a calculator. -
Correct: Please bring a pen, a notebook, and a calculator.
Introducing Explanations.
Use a colon to introduce an explanation or elaboration:
-
She had one goal: to finish her degree.
-
The answer was clear: we needed more data.
Introducing Quotations.
When a full sentence introduces a quotation, a colon is appropriate:
-
The professor made her position clear: "We will not accept late submissions."
When the quotation flows as part of the sentence, use a comma or no mark:
-
She said, "I’ll be there." (comma—flows into the quote)
-
He called it "a masterpiece." (no mark—integrated into the sentence)
In Formal Contexts.
Between titles and subtitles:
-
Grammar Matters: A Guide to Standard English
After salutations in formal letters:
-
Dear Dr. Smith:
