describe how you would verify that a protein is either native or denatured?

Answer 1

Depends on the protein.
If it is an enzyme do the respective enzymatic test.
In general, take the circular dichroism spectrum (it's a function of protein structure).
You can also run a native PAGE and an SDS-PAGE and compare. It's not as informative as the CD spectrum but not all labs have a CD spectrophotometer...