An appositive phrase is a group of words in a sentence that adds more information. Because this is extra information, it could be left out and the sentence would still make sense.
Here is a simple sentence: Bob has a new lawn mower.
The reader might wonder, who is Bob? So we can add some extra information.
Bob, my next-door neighbor, has a new lawn mower.
The words my next-door neighbor are an appositive phrase. We put commas around this group of words to show that it is extra information and could be left out without ruining the meaning of the sentence.
Here are more examples of sentences with an appositive phrase:
Jim is playing basketball this year. Jim, my oldest brother, is playing basketball this year.
Susie lost her doll. Susie, my little cousin, lost her doll.
Sometimes, the extra information is at the end of the sentence. When that happens, only one comma is needed.
I attended Northwestern University, my dad’s alma mater.
An appositive phrase is a group of words giving more information in a sentence. Use a comma before and after an appositive phrase.
▶It’s your turn: Use a comma or commas to set off the appositive phrase in this sentence: Sam my best friend is moving to Wisconsin. Did you put two commas into this sentence? Good for you!