The Use of Parenthetical Elements

A parenthetical element is the information, which is insignificant to the sentence’s meaning, like a clarification or an example. Such elements often include the following phrases:

• Relative items that usually begin with which, who, when, where
• Participial phrases, which describe preceding nouns
• Appositives, which rename preceding nouns
• Prepositional phrases, which describe preceding nouns
• Phrases that begin with including, such as, i.e., e.g.

The additional information, which is provided by parenthetical elements, is usually enclosed by two commas, parentheses or dashes that separate the nonessential information from the rest of the sentence.

Commas

Commas are often used as an interruption, like in the examples below:

• Blackberry jam, for example, does not make a good pizza sauce.
• Aunt Mary, when she was told about the good news, cried from happiness.
• Johns, although he is usually moody, likes an occasional chuckle.
• The tone of her letter, however, brought tears to Fang’s eyes.
• Julia, it seems, loves peanuts more than pistachios.

In all the examples above, the phrases, which are bracketed by commas, are parenthetical elements. In simple words, the sentence “Blackberry jam, for example, does not make a good pizza sauce” will not change its meaning if you remove the parenthetical element from it.

Parentheses

Like commas, these punctuation marks are used to separate the insignificant information from the rest of the sentence. Note that a parenthesis helps emphasize its content a bit more than a comma does. Furthermore, it is not necessary to make any specific grammatical connection to the rest of the text. Here are several examples:

• According to the probability theory, chances are great (88%) that he will succeed!
• Jane (10 years old) is a girl who goes to classes with my sister.

Dashes

These punctuation marks are usually used to strongly accent a parenthetical element, conveying an unexpected change in content or tone. For example, in the sentence “His birthday party – surprisingly! – was a lot of fun” the dashes strengthen the sudden nature of the finding. Note that in scientific writing parentheses and commas are used more often than dashes.

Also, dashes are sometimes used in order to set off a parenthetical element that contains commas, like in the following sentence: “Putting a spin on an object – a top, a bullet, a satellite – gives it balance and stability.”