What’s the Difference Between ( ), [ ], { } and < >?

( )

Parentheses (the single one is called a parenthesis), also known as curved brackets, have plenty of uses in everyday written language. Their most common use, as I’ve demonstrated already, is segregating subordinate material or asides. Usually, this is stuff that could be left out of the text or skipped over during reading without altering the flow or meaning of the surrounding sentence. You can do the same thing with commas, like I did in the last sentence and am doing now, but, if you’ve got a few commas in the sentence for other purposes, things can get a little out of hand, like they might be here.

In cases where a writer is uncertain whether a subject(s) is singular or plural, or male or female, and (s)he wants to cover all the bases, parentheses denote that things could be one or the other.

Parentheses also have a few uses in mathematics, and are used to denote sets of coordinates, set aside the arguments of functions and set precedence in the order of operations. You might remember the mnemonic device PEMDAS (or BODMAS or BEDMAS if you’re from the UK or Canada) from math class: in a calculation, you do the stuff in parentheses first, then exponents, then multiplication and division, and finally addition and subtraction (left to right on those last four).

[ ]

Square brackets are primarily used to modify quoted text by someone who isn’t the original author. These modifications might include…

  • Adding clarification - “He [the sheriff] shot them [the zombies] in the head.”
  • Adding missing information - “The zombies had come into the city from two adjoining counties [Butler and Beaver].”
  • Adding missing words - “Where [are] the zombies at?”
  • Adding editorial comment - “If you are bitten by a zombie, do not try to hide it from your fellow survivors.” [emphasis mine]
  • Adding an ellipsis or the Latin word sic to indicate deleted material or that the text is quoted exactly as it appeared in the original source - “Oh muh gawd [sic], the zombies are coming through the window […]”

Square brackets can also be used to nest subordinate text within subordinate text (this is done by putting square brackets [like these guys] inside parentheses).

In mathematics, square brackets are used to denote floor and ceiling functions, commutators, matrices, intervals and other things that I don’t understand.

{ }

Curly brackets, sometimes called squiggly brackets or braces, don’t see much use in everyday writing, but do pop up in poetry (to join triplet lines), music (to mark grace notes), math (to list members of a set) and different programming languages (to enclose groups of statements).

< >

Chevrons, or angle brackets, are also largely confined to specialized use. In programming markup language, like html, tags and other statements. In comic books, graphic novels and video games, they’re sometimes placed around dialog to indicate that the character is speaking another language and you’re reading the translation. On TV, they're sometimes placed around the names of sounds (<explosion>) to interpret sound effects in closed captions. In mathematical calculations they’re used to indicate that one number is less than or greater than another.

In more common usage, especially in online conversation, they’re used to make text hearts (<3) or indicate a writer’s physical actions <waves goodbye>.

Big Questions
Are There Number 1 Pencils?

Almost every syllabus, teacher, and standardized test points to the ubiquitous No. 2 pencil, but are there other choices out there?

Of course! Pencil makers manufacture No. 1, 2, 2.5, 3, and 4 pencils—and sometimes other intermediate numbers. The higher the number, the harder the core and lighter the markings. (No. 1 pencils produce darker markings, which are sometimes preferred by people working in publishing.)

The current style of production is profiled after pencils developed in 1794 by Nicolas-Jacques Conté. Before Conté, pencil hardness varied from location to location and maker to maker. The earliest pencils were made by filling a wood shaft with raw graphite, leading to the need for a trade-wide recognized method of production.

Conté’s method involved mixing powdered graphite with finely ground clay; that mixture was shaped into a long cylinder and then baked in an oven. The proportion of clay versus graphite added to a mixture determines the hardness of the lead. Although the method may be agreed upon, the way various companies categorize and label pencils isn't.

Today, many U.S.  companies use a numbering system for general-purpose, writing pencils that specifies how hard the lead is. For graphic and artist pencils and for companies outside the U.S., systems get a little complicated, using a combination of numbers and letters known as the HB Graphite Scale.

"H" indicates hardness and "B" indicates blackness. Lowest on the scale is 9H, indicating a pencil with extremely hard lead that produces a light mark. On the opposite end of the scale, 9B represents a pencil with extremely soft lead that produces a dark mark. ("F" also indicates a pencil that sharpens to a fine point.) The middle of the scale shows the letters and numbers that correspond to everyday writing utensils: B = No. 1 pencils, HB = No. 2, F = No. 2½, H = No. 3, and 2H = No. 4 (although exact conversions depend on the brand).

So why are testing centers such sticklers about using only No. 2 pencils? They cooperate better with technology because early machines used the electrical conductivity of the lead to read the pencil marks. Early scanning-and-scoring machines couldn't detect marks made by harder pencils, so No. 3 and No. 4 pencils usually resulted in erroneous results. Softer pencils like No. 1s smudge, so they're just impractical to use. So No. 2 pencils became the industry standard.

WANG ZHAO/AFP/Getty Images
Big Questions
What Are Curlers Yelling About?
WANG ZHAO/AFP/Getty Images
WANG ZHAO/AFP/Getty Images

Curling is a sport that prides itself on civility—in fact, one of its key tenets is known as the “Spirit of Curling,” a term that illustrates the respect that the athletes have for both their own teammates and their opponents. But if you’re one of the millions of people who get absorbed by the sport once every four years, you probably noticed one quirk that is decidedly uncivilized: the yelling.

Watch any curling match and you’ll hear skips—or captains—on both sides barking and shouting as the 42-pound stone rumbles down the ice. This isn’t trash talk; it’s strategy. And, of course, curlers have their own jargon, so while their screams won’t make a whole lot of sense to the uninitiated, they could decide whether or not a team will have a spot on the podium once these Olympics are over.

For instance, when you hear a skip shouting “Whoa!” it means he or she needs their teammates to stop sweeping. Shouting “Hard!” means the others need to start sweeping faster. If that’s still not getting the job done, yelling “Hurry hard!” will likely drive the point home: pick up the intensity and sweep with downward pressure. A "Clean!" yell means put a brush on the ice but apply no pressure. This will clear the ice so the stone can glide more easily.

There's no regulation for the shouts, though—curler Erika Brown says she shouts “Right off!” and “Whoa!” to get her teammates to stop sweeping. And when it's time for the team to start sweeping, you might hear "Yes!" or "Sweep!" or "Get on it!" The actual terminology isn't as important as how the phrase is shouted. Curling is a sport predicated on feel, and it’s often the volume and urgency in the skip’s voice (and what shade of red they’re turning) that’s the most important aspect of the shouting.

If you need any more reason to make curling your favorite winter sport, once all that yelling is over and a winner is declared, it's not uncommon for both teams to go out for a round of drinks afterwards (with the winners picking up the tab, obviously). Find out how you can pick up a brush and learn the ins and outs of curling with our beginner's guide.

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