When I was a boy at a Public School I was taught that in some circumstances the subject and the object of the verb "to be" can be different in singularity/plurality.
I find support for find this on the Internet -
link
Summary: None can be singular or plural, unless it quantifies a singular or mass noun . Don’t believe anyone who says none has to be singular because it’s a contraction of not one . Both none of the meals is and none of the meals are are okay, and both none is and none are are okay. *None of the stuff are is ungrammatical, though.