Parentheses ( ( ) )

Parentheses are used for enclosing words, phrases, or clauses which might not be grammatically related to the rest of the sentence. This may include comments, examples, appositives, numbers or acronyms. Dashes or commas can often serve the same purpose.

Appositives

• The Centers for Disease Control and Prevention ( CDC ) has called insufficient sleep an epidemic.
• The hammerhead species that branched off the earliest is the winghead shark ( E. blochii ) , which has one of the widest heads.
• In insects, these are found only in the scales of weevils, longhorn beetles, butterflies and moths, where they can form intricate arrays of chitin ( the material that makes up the bulk of the exoskeleton of insects ) and air.

Other Examples

• These are animals or other organisms that live on ( ectoparasites )closing parenthesis or in ( endoparasites ) another species.
• Since the 1960s we have known that new ocean crust is being created almost continuously along giant rifts ( called mid-ocean ridges ) .
• At the bottom of the plates, around 60 miles ( 100 kilometers ) deep, the temperature is about 2,400 degrees Fahrenheit ( 1,300 degrees Celsius ) .

Test your understanding of apostrophe and parentheses punctuation with the Apostrophe - Parentheses Punctuation Quiz.