An appositive is a noun that renames another noun. The two words are found next to each other in a sentence. Here is an example:

My teacher, Mrs. Worley, is nice most of the time.

Mrs. Worley is the appositive because it RENAMES the noun teacher.

1. Carrie, my best friend, is in my wedding.

2. My best friend, Carrie, is in my wedding.

3. The little boy gave his girlfriend, Sally, a love letter.