O.K read up on this board and just want to make sure I got it.

Given:
Right now I have 1/2 subfloor on 16" o.c.
Great room 30x26 including kitchen area
In the kitchen area there is another 1/2" plywood on top of the 1/2" subfloor.
Everywhere else is 5/8 particle board (not OSB) on top of 1/2" subfloor.
I want to install hardwood either 3/4 or engineered. OR even VLP to last a few years but in the end hardwood.

I believe from what I have read is to remove the particle board and replace it with 1/2" plywood on top of the existing 1/2" subfloor.
Is this correct
Should I go with more than 1/2"
Plywood or OSB?
Glue till glue and screw?

Thanks
v1

if you nail it will serve you to replace it..if you glue it will be of no consequence to leave the particle board