Polite parents teach their young children not to interrupt conversation. When someone is excited, it's sometimes hard to follow this rule about good manners, but most people generally know interrupting others, unless it is in an emergency situation, is not good etiquette. In the world of grammar, therefore, we set off those interrupters with the use of commas.
Rule: Use commas to set off expressions that interrupt the sentence.
Appositives and appositive phrases are usually set off by commas.
An appositive is a noun or pronoun that follows another noun or a pronoun to identify or explain it. An appositive phrase consists of an appositive and its modifiers.
Examples with appositive and appositive phrases in bold:
1. We visited Boston harbor, the site of the Boston Tea Party.
2. George Washington, our first president, was a great military leader.
3. Travelers should give careful thought to footwear, the most crucial item of apparel.
4. Ms. Seagro, our French teacher, has studied at the Sorbonne.
*Note: When an appositive is so closely related to the word it modifies that it appears to be part of that word, no comma is necessary. (An appositive of this kind is called a restrictive appositive, and it is usually one word.)
Examples with restrictive appositives in bold:
1. My nephew Jim is an architect.
2. The expression c'est la vie is used occasionally in everyday English conversation.
3. The American gymnast Peter Vidmar is an Olympic Gold Medalist and one of the top 10 motivational speakers in the country.
*(Other interrupters set off by commas include words used in direct address and parenthetical expressions which I will address later.)
Appositives and appositive phrases are useful in your writing because they add important information for the readers. So, remember to please use good manners and set off appositives and appositive phrases with commas unless they are closely related to the word they further explain, and the grammar gods will smile upon you.
Don't forget National Grammar Day is on March 4th! Help us celebrate and help focus attention on speaking and writing well! More information on this and related activities can be found at http://nationalgrammarday.com/
