Parentheses are like polite back seat drivers. (They interrupt to explain additional information that the reader should know.) Parentheses can hold explanations, illustrations, or clarifications.
According to legend, the Greek playwright Aeschylus was killed when an eagle dropped a tortoise on his bald head (mistaking it for a rock).
Many great writers died before the age of forty (Byron was 36; Nathanael West, Rimbaud, and Robert Burns were 37; Thomas Wolfe and Pushkin were 38; and Dylan Thomas was 39).
I told him I absolutely believe in marriage (as a cure for the temporary insanity of infatuation).
Parentheses are also used to set off dates, provide reference information, and to enumerate a list.
Angela Merici (1470-1540), an Italian, founded the Ursulines in 1535, an unconventional religious order in which women took vows but lived at home and taught in the community.
The Chinese poet Li Po (c.700-762), a "lighthearted winebibber," fell out of a boat and was drowned when he tried to kiss and embrace the moon's reflection in the water (Hendrickson 111).
The reason there are so many popular bike trails outside of Washington, D.C., is that the land is mostly flat (see contour map on page 6).
If your toddler does not sleep through the night there are several questions to ask: (1) Have you developed a soothing bedtime ritual? (2) When checking on your child, do you accidentally wake him or her? (3) Is your toddler afraid of the dark? (4) Is your toddler waking regularly in the night hungry or thirsty? (5) Does your toddler use a pacifier or "cuddly" so he or she is able to comfort himself or herself?
Note: Punctuate correctly in and around parentheses. If a whole sentence is inside parentheses, then put the period inside the end parenthesis. If only part of the sentence is in parentheses, then the period goes outside of the end parenthesis.