What is the appositive phrase in this sentence?

Martha, my best friend, is coming on vacation with me.

my best friend THIS ONE
Martha
coming on
vacation with me

i like how there is no period, so it's just THIS ONE

Yes, you're right.

The appositive phrase in the sentence "Martha, my best friend, is coming on vacation with me" is "my best friend".

The appositive phrase in the given sentence is "my best friend."

To identify the appositive phrase, we need to look for a noun or pronoun that provides additional information about another noun or pronoun in the sentence. In this case, "my best friend" provides additional information about "Martha." It further describes who Martha is.