[ ] Brackets (US), Square Brackets (UK) [….]

[ ] Brackets, known by that term in the US and as square brackets in the UK, come in pairs and enclose a stretch of text. Generally, they are used to indicate added text that explains or comments on something in a sentence.

[ ] Brackets / Square Brackets

What are brackets?

The punctuation marks […], as opposed to parentheses (…), show that something has been added to or omitted from a quotation or cited sentence—the material within the brackets is often an explanation or a comment on something in the original quotation.

When to use brackets

They may be used when a writer wants to explain or comment on something in a quotation.

Examples:

• “Willie Mays [inducted into the Baseball Hall of Fame in 1979] began his professional career in 1947.”
  
• “The history of all hitherto existing society [by this Marx meant written history] is the history of class struggle.”
  
• “The Toyota RAV4 [see our full review in the May issue] continues its run as a popular small SUV.”
  
• “A meal at that restaurant will cost you $100 [90 euros].”
  
• “This year, we plan to expand the zoo [with new animal displays],” the director said.
  
• “The Beijing Metro [don’t try to board at rush hour unless you like being squashed!] is one of the world’s busiest transportation systems.”
  
• “Jean-Luc Godard [still active although he is almost 90 years old] was a key figure in the French cinematic movement known as the New Wave.”
  
• “Teresa Teng [traditional Chinese: 鄧麗君] was among the most popular singers ever to have emerged from the Chinese-speaking world.”

The ellipsis in brackets—use an ellipsis (UK: ellipsis points) to show that words have been omitted from a quotation.

Examples:

• “If you visit Berlin, you’ll probably want to visit the Tiergarten, a public park containing a zoo […], public gardens, and recreation areas.”
  
• “Mozart’s compositions include 41 symphonies, more than a dozen operas […], and numerous pieces of chamber music and keyboard music.”
  

You can use these marks around a single letter to modify a word in a quotation so that it will fit into a new sentence. Often this is done to remove a capital letter from a quoted sentence within another sentence.

• Ho Chi Minh famously said that “[i]t was patriotism, not communism, that inspired me.”
  
• When you’re having hard times, remember Winston Churchill saying that “[i]f you’re going through hell, keep going.”

This usage is restricted to formal writing, where exact reproduction of a quotation is important. In informal writing, you can simply use the lowercase letter.

[Sic]

The expression “sic” (Latin for “just as”) is often used in brackets to show that an error in a quotation appears in the original text rather than resulting from an error by the writer.

• The oil was stored in 55-galon [sic] drums that later were discarded and had their tops turned into musical instruments.

Brackets / Square Brackets Infographic

Learn more with useful punctuation rules on how to use parentheses and quotation marks in English with examples and infographics.