Colons and semicolons

A colon ⟦:⟧ introduces something: a list or an explanation. A semicolon ⟦;⟧ joins two main clauses that are closely linked, or separates the items of a long list. ⟦You will need three things: a pen, a ruler and a rubber.⟧ ⟦It was raining; we stayed inside.⟧

Key facts

  • A colon introduces a list. The words before it must be a complete sentence: ⟦We visited four countries: Egypt, Jordan, Oman and Kenya.⟧
  • A colon can introduce an explanation or a reason: the second part explains the first. ⟦I couldn't sleep: the dog barked all night.⟧
  • A semicolon joins two main clauses that are closely linked. Each could be a sentence on its own: ⟦Mia loves maths; her brother prefers art.⟧
  • A semicolon separates list items that already contain commas: ⟦We visited Cairo, Egypt; Rome, Italy; and Paris, France.⟧
  • After a colon or a semicolon, carry on with a small letter (unless the word is a name or ⟦I⟧). A comma can't join two sentences: ⟦It was raining, we stayed inside.⟧ is wrong.

Worked examples

Example 1

Join with a semicolon: ⟦The road was icy. The cars moved slowly.⟧

  1. Both parts are main clauses and they are closely linked.
  2. Replace the full stop with a semicolon and use a small letter: ⟦The road was icy; the cars moved slowly.⟧

Answer: ⟦The road was icy; the cars moved slowly.⟧

Example 2

Add a colon: ⟦The recipe has three ingredients flour, eggs and milk.⟧

  1. ⟦The recipe has three ingredients⟧ is a complete sentence.
  2. The list comes after it, so the colon goes there.

Answer: ⟦The recipe has three ingredients: flour, eggs and milk.⟧

Example 3

Colon or semicolon? ⟦She was delighted ___ she had won first prize.⟧

  1. Why was she delighted? Because she had won.
  2. The second part explains the first, so use a colon.

Answer: ⟦:⟧