What is the appositive in the sentence: "My brother Mike is getting to be a big boy."?
An appositive is a noun that renames another noun, and they're always right next to each other. Mike renames "brother", so Mike is the appositive. An appositive can be just one word or a whole phrase.
Check out this link: https://owl.english.purdue.edu/owl/resource/596/01/
Hope this helps!