Grammar rule

Semicolons and colons

A semicolon joins two complete sentences; a colon introduces something after a complete sentence.

Updated October 29, 2026

The rule

Use a semicolon only where a period could go: both sides must be complete sentences. (It can also separate list items that already contain commas.)

A colon must follow a complete sentence. It introduces a list, an explanation or a quotation: "She packed three things: a map, a flashlight and water." Never put a colon right after a verb or a word like "including".

Examples

  • We need: eggs, milk and flour.We need eggs, milk and flour.
  • I studied all night; and I passed.I studied all night, and I passed.

Quick test: Test the words before a colon or on both sides of a semicolon: could they end with a period?

Try it: find the mistake

The mistake in each sentence is highlighted. Say the fix out loud, then open the answer.

My favorite subjects are: math, art and music.

My favorite subjects are math, art and music.

A colon must follow a complete sentence. "My favorite subjects are" isn't one, so no colon.

I love to read; especially mysteries.

I love to read, especially mysteries.

A semicolon needs a complete sentence on both sides. "Especially mysteries" isn't one.

We packed sandwiches; and drinks for the trip.

We packed sandwiches and drinks for the trip.

No mark is needed between two items joined by and.

The recipe needs three things; flour, sugar and butter.

The recipe needs three things: flour, sugar and butter.

A complete sentence introduces a list, so use a colon.

Play today's Grammar Fix, free

Where this rule is tested

  • The CLT's Grammar/Writing section and the SAT's Reading and Writing section both test it, usually as "which choice is correct" with four versions of a sentence.
  • In the Daily Grammar Fix, it comes up in sentences for grades 7 to 9 and grades 10 to 12.

Questions people ask

What is the rule for semicolons and colons?

A semicolon joins two complete sentences; a colon introduces something after a complete sentence. Use a semicolon only where a period could go: both sides must be complete sentences. (It can also separate list items that already contain commas.)

How can I check my semicolons and colons quickly?

Test the words before a colon or on both sides of a semicolon: could they end with a period?

Where can I practice this for free?

In Owl Test Prep's Daily Grammar Fix: one sentence a day for everyone, plus practice sets of five on this rule. It is free, with no account.

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