Round, round, get around, I get a … square?

Bill Bryson: You'd better believe this man knows his way around a square bracket.

Bill Bryson: You'd better believe this man knows his way around a square bracket.

This week’s blog topic comes courtesy of one of our readers. She asks: “Why do people sometimes use square brackets? What’s the difference between square and round?” (By the way, if you have a grammar question, we’d love to answer it for you. Just email us or get in touch via our Facebook page.)

Round brackets ( )

Round brackets are used to show asides – extra bits of information that aren’t crucial to the meaning of the written text. These asides can be a single word, a whole paragraph or anything in between. Here are some examples I found by flicking through Bill Bryson’s Mother Tongue, which is an excellent book and also happened to be the only one I could reach without moving from my chair:

Altogether, about 200,000 English words are in common use, more than in German (184,000) and far more than in French (a mere 100,000).

The Italians even have a word for the marks left on a table by a moist glass (culacino) while the Gaelic speakers of Scotland, not to be outdone, have a word for the itchiness that overcomes the upper lip just before taking a sip of whisky. (Wouldn’t they just?)

Even those who were cut off from the twenty or so great language families developed their own quite separate languages, such as the … Ainu language spoken on the northern island of Hokkaido in Japan by people who have clear Caucasian racial characteristics and whose language has certain (doubtless coincidental) similarities with European languages. (For instance, their word for eighty is “four twenties”.)

As you can see, all the words in round brackets could be deleted without affecting the grammar or meaning of the sentences. The information in brackets is interesting but not crucial.

Before we move on to square brackets, here are a few bonus tips and observations:

  • Round brackets are called “parentheses” in American English.

  • You should never use round brackets in dialogue or quoted speech. People don’t speak in brackets. Instead, use a pair of commas or dashes to serve the same purpose.

  • When you have a full sentence inside round brackets, keep that sentence’s punctuation inside the brackets (as Bryson does with the question mark after “Wouldn’t they just”).

  • Sometimes the inclusion of round brackets makes grammar a bit tricky. For example, in the sentence Bill Bryson (and a friend) ____ walking the Appalachian Trail, should the missing word be was (singular, relating only to Bryson) or were (plural, relating to Bryson and his friend)? To find out, just imagine removing the bracketed phrase altogether. The sentence has to make sense without it, so the correct answer is was, singular.

  • Brackets are sometimes used around single letters in sentences like this: The client can, if (s)he wishes, seek advice on the matter(s) from a third party. Here, the brackets signify alternatives – they’re a quicker way of saying “he or she” and “matter or matters”. As in our earlier examples, it’s important to make sure that the sentence would still make grammatical sense if the bracketed letters were removed.

Square brackets [ ]

Unless you’re a journalist or an academic, you probably don’t use square brackets very often. That’s because they serve a very specific purpose: they’re used in quotations to show that the original quotation has been altered by the writer, usually to improve clarity, fix an error or add extra information. For example:

“Like other writers of the period, he [Chaucer] appeared to settle on whichever form first popped into his head,” Bryson writes in the chapter about early English.

Bryson’s bestselling 2006 memoir wasn’t quite universally loved. One Goodreads reviewer wrote, “What is [jarring] and unacceptable are the factual errors in every chapter.”

When asked about his greatest fear in a recent interview, Bill Bryson responded, “Being stuck in a broken lift with [British journalists] Piers Morgan and Janet Street-Porter.”

Here are some extra titbits about square brackets:

  • Americans just call them “brackets”, since they have no need to differentiate between square and round.

  • Journalists tend to put clarifications in square brackets and then delete the old word or words altogether. For example, in the sentence above, most journalists would write Like other writers of the period, [Chaucer] appeared to settle …, dropping the pronoun he. Although this is common practice, the official rule is that you should leave the original words in. (This doesn’t apply, however, to spelling/grammar corrections – in those cases, you can delete the errors.)

  • You’ve probably seen square brackets used around the word “sic” in news stories. “Sic” means “so” or “thus” in Latin, and is always italicised because it is in a foreign language. Basically, we use it to say, “We know this is an error, but it’s what the person we’re quoting actually said/wrote.” For example, the Goodreads review I mentioned above misspells “jarring”. If you were quoting said review, you could either do what I did and replace the error with “[jarring]” or leave it misspelt but add “[sic]” afterwards: What is jaring [sic] and unacceptable …


Remember when we talked about nesting in regard to quotation marks? Technically, the same principle applies with brackets: When you have brackets within brackets, you should differentiate them by making the internal brackets square, like so:

Although Bill Bryson is American (he was born in Des Moines [Iowa] in 1951), he has lived in the UK for much of his adult life.

As you can see, the nested square brackets look ridiculous and could easily be replaced with commas: he was born in Des Moines, Iowa, in 1951. I’m yet to come across a sentence that really needs two sets of brackets, so, if I were you, I wouldn’t worry too much about the whole nesting issue.

In a nutshell

Use round brackets for asides – bits of information that aren’t crucial to the meaning or grammatical sense of the sentence. Use square brackets when you’re quoting someone else and want to indicate that you’ve altered their words somehow.