Rule 5. More commas: parenthetical phrases

 When you have a group of words that describe a noun whose meaning is already clearly defined, you set off the group of words with commas. The phrase is similar to a parenthetical expression that contains nonessential information. If you remove the phrase from the sentence, the meaning does not change drastically. Some meaning may be lost, but the essential characteristics remain.

For basketball camp, the children needed high quality sneakers, which were expensive.

In this example, the essential information is that the children needed good sneakers in order to go to basketball camp; the fact that the sneakers were expensive is more of an afterthought and thus it is set off with a comma.

The dessert made with fresh raspberries was delicious.

The dessert, made with fresh raspberries, was delicious.

The first example has no commas because the phrase “made with fresh raspberries” is essential information which tells the reader which of several desserts the writer is referring to. The second example has commas because the phrase “made with fresh raspberries” adds nonessential information about the dessert.

The rule of thumb here is that if you can remove the phrase from the sentence without losing any essential meaning, then it should be set off with commas.

Practice:

  1. My older brother who played tight end on our high school football team now lives at The Oaks a condominium complex near Detroit.
  2. The Ghostbuster Vac which is a 25 pound vacuum cleaner is designed to be worn on a maintenance person’s back.
  3. The African American woman running for the House of Representatives from Georgia is the one who has a long history of community service.
  4. The title role in Neil Simon’s comedy, Barefoot in the Park, was performed splendidly by the young actor, Matt LeBlanc.
  5. Attending law school which has always been an ambition of mine now seems out of the question.
  6. The driver of a car who is responsible for the safety of his passengers should be willing to take a breathalyzer test to demonstrate his capacity to drive safely.

Click here for suggested answers