What type of modifier is this?

[yo4561]

My favorite question to ask

Let's say I have this example "Hannah discovered that it was James who stole her cookies, not Josh or anyone else."

To confirm, is the "not Josh or anyone else" an adverbial modifier?

[esledge]

First, please accept our apologies for the late response. A tech glitch has hidden this folder from all logged-in Manhattan Prep staff since the New Year, so I didn’t see this question until now.

A practical technique I use for this is to pretend I am on Jeopardy! the quiz show, and turn the modifier into a question. If the answer is a verb, it's an adverbial modifier. If the answer is a noun, it's a noun modifier. So let's do this with something we know is a modifier:

Who stole her cookies? James. So "who stole" is a noun modifier.

I'm not sure the underlined part is a modifier, though. The "not" almost seems like a parallelism marker:

James, not Josh or anyone else, stole her cookies.

This makes "Josh/James/Anyone" parallel subjects that all share the verb "stole." Does putting the "not" part at the end of the sentence change anything about this? Your sentence definitely has a more complex structure, but I think the "not" part is still just a parallel with "James," so if it's a modifier at all, it's a noun modifier.