Parenthesis: brackets, dashes and commas

Parenthesis is a word or phrase added to a sentence to give extra information. We put a mark on both sides of it: brackets, a pair of dashes or a pair of commas. If you take the extra information out, the sentence still makes sense: ⟦My uncle (who lives in Cairo) is visiting.⟧

Key facts

  • Brackets go around the extra information: ⟦The Nile (the longest river in Africa) flows north.⟧
  • A pair of dashes does the same job and makes the extra information stand out: ⟦The test – to everyone's surprise – was easy.⟧
  • A pair of commas is the most common way, and the least noticeable: ⟦Omar, our team captain, scored the goal.⟧
  • Always use a pair: the mark at the end matches the mark at the start. Don't open with a bracket and close with a comma.
  • Test it: take the parenthesis out. ⟦My uncle is visiting.⟧ is still a complete sentence, so the marks are in the right place.

Worked examples

Example 1

Add a pair of commas: ⟦Our teacher Mrs Patel gave us homework.⟧

  1. ⟦Mrs Patel⟧ tells us more about the teacher.
  2. Put a comma on each side: ⟦Our teacher, Mrs Patel, gave us homework.⟧

Answer: ⟦Our teacher, Mrs Patel, gave us homework.⟧

Example 2

Which words are the parenthesis? ⟦Penguins – unlike most birds – cannot fly.⟧

  1. The words between the dashes are ⟦unlike most birds⟧.
  2. Take them out: ⟦Penguins cannot fly.⟧ still makes sense.

Answer: ⟦unlike most birds⟧

Example 3

Correct it: ⟦The cake (which Mia baked, was delicious.⟧

  1. It opens with a bracket, so it must close with a bracket.
  2. ⟦The cake (which Mia baked) was delicious.⟧

Answer: ⟦The cake (which Mia baked) was delicious.⟧