Appositives and Punctuation
By Daniel (with the help of Marcus and Itbaan)
Appositives
An appositive is a noun that is used to describe or define another noun. For example, my computer, an Apple Mac Pro, is very reliable for completing my schoolwork. In this sentence, the computer defines the Apple Mac Pro, conveying that the Apple Mac Pro is a computer.
Punctuation of Appositives
To punctuate an appositive, there are two rules. If the information in the sentence is essential to the meaning of the sentence, then leave the appositive alone by not placing commas around it. If the sentence would be clear without an appositive, then commas are necessary.
Example