The ways of John (is/ are) are good !
Are indefinite pronouns the ones that could be singular or plural ever tested, I've seen hundreds of questions, none seem to be tested.
They can't be tested easily (at least in terms of discerning between singular and plural as the decisive element in the question) because you can argue that either is correct in some cases.
In this example, clearly you want "are" because they ways
are. John is
, but we don't care about John, just about his ways.