Brackets are symbols that we use to contain "extra information", or information that is not part of the main content. Brackets always come in pairs—an "opening" bracket before the extra information, and a "closing" bracket after it. There are two main types of bracket: round () and square . British English and American English define them differently, as you see below.
Round Brackets or Parentheses
( ) = round brackets or brackets
( ) = parentheses
Round brackets are basically used to add extra information to a sentence. Look at these examples:
- explain or clarify
- Tony Blair (the former British prime minister) resigned from office in 2007.
- Please leave your mobile telephone(s) at the door.
- Many people love parties (I don't).
- The matter will be decided by the IOC (International Olympic Committee).
Some grammarians believe that (whenever possible) we should use commas.
Some grammarians believe that, whenever possible, we should use commas.
Remember that the full stop, exclamation mark or question mark goes after the final bracket (unless the brackets contain a complete sentence). Look at these examples:
- My car is in the drive (with the window open).
- I just had an accident with our new car. (Sssh! My husband doesn't know yet.)
- The weather is wonderful. (If only it were always like this!)
- The party was fantastic (as always)!
- Do you remember Johnny (my brother's friend)?
- Johnny came too. (Do you remember Johnny?) We had a great time.
Square Brackets or Brackets
[ ] = square brackets
[ ] = brackets
We typically use square brackets when we want to modify another person's words. Here, we want to make it clear that the modification has been made by us, not by the original writer. For example:
- to add clarification:
- The witness said: "He [the policeman] hit me."
- to add information:
- The two teams in the finals of the first FIFA Football World Cup were both from South America [Uruguay and Argentina].
- to add missing words:
- It is [a] good question.
- to add editorial or authorial comment:
- They will not be present [my emphasis].
- to modify a direct quotation:
- He "love[s] driving." (The original words were "I love driving.")
We also sometimes use square brackets for nesting, for example:
- Square brackets can also be nested (using square brackets [like these] inside round brackets).